How To
Terrariums Part 1: Introduction
Part 1 of a 3 part series
A miniature world under glass, terrariums are fascinating and remarkably easy to create and maintain! Over the next 3 posts, I will be discussing everything you need to know about designing, planting, and maintaining terrariums.

I first got into terrariums a few years ago when my colleague James starting collecting glass bell jars and specimen begonias. I must confess his enthusiasm was contagious! I now have two and have given one to my sister. Plants have been grown under glass since Victorian times. In those days they were commonly referred to as Wardian cases, named after Dr. Nathaniel Ward who first introduced society to these mini ecosystems.
It is so easy to grow terrarium plants in enclosed environments, because they need not be constantly watered or groomed. In their native habitat, plants requiring extra humidity were growing on the floor of the rainforest, in tree crevices or on rocks with a thick canopy of growth overhead. The most important things to remember about their care are to keep the containers out of direct sunlight, and to try and keep them on the cool side. Many unsuccessful growers have forgotten that the plants love humidity, but they do not like wet feet.
There are a few things to consider before planting your terrarium:
- Make sure the plants you select are the appropriate scale for the container and the other plants, otherwise it will dominate the design
- Select plants that are completely different from each other in terms of color, leaf shape and growing habit. The key is for each plant to have its own unique personality, instead of them all blending together.
- Don’t be discouraged if a plant doesn’t make it. Terrariums are a learning experience and may take a little time to gauge how much or little water is needed. Proper plant choices will minimize this issue.
Check back in a few days for part 2 of this series: Creating Open Terrariums and more great planting inspiration.
For a quick how-to: Click Here
How to Plant an Orchid
An orchid ready to be pottedOrchid
While light requirements vary depending on the variety, as a general rule most orchids prefer filtered to bright light. For long-term health, orchids do not do well in lowlight environments.
Orchid Pot: Notice the holes for air circulation and drainageOrchid Pot
Orchid roots do not like to be confined. Orchid pots have holes to allow for the best air circulation and drainage for your plants. If you prefer a standard non-perforated pot, make sure the planting medium is extremely loose.
How to Build a Terrarium
You’ll need:
Glass Terrarium ContainerGlass Container
Your terrarium needs to be large enough to contain plants, decorative elements and some “breathing space.” A large jar, fishbowl or shallow glass bowl also work great.
Small Plants: These 1” pots are perfectSmall Plants
Mini plants (as opposed to young plants) will not outgrow the size of the container. Be sure to group together plants that have the same sunlight requirements.
GravelGravel for Drainage
Inadequate water drainage is the biggest problem facing mini gardens and terrariums. A layer of small gravel will allow for your terrarium to drain.
Activated CharcoalCharcoal
A layer of charcoal will filter the water and help prevent fungi from forming in your terrarium. You’ll be glad you added this!
Potting SoilLight Potting Mix
Your soil must maintain the proper balance between water & nutrient retention, and adequate drainage. Mahoney’s Premium Potting Mix is perfect.
Decorative ElementsDecorative Elements
Think of your terrarium as a miniature landscape - use mini decorative figures such as benches, birdhouses, urns, fairies or even mini-houses. Add moss or rocks for a finished look.
How to build your terrarium
- Start off with a bottom layer of gravel,
- Add a ¼ inch layer of gardener’s charcoal.
- Next, add a layer of soil. Arrange your plants and fill the empty spaces around the roots with soil.
- Lastly, you can either do a layer of sphagnum moss or an assortment of other botanicals. I prefer to use lots of different things to add texture, color and visual interest. Some of my many favorites include reindeer moss, lichen, pinecones, pods, river stones and tallow berries. I love talking a stroll through the woods to find some of these mosses, lichen covered branches and interesting stones. A cute little critter nestled in, such as a bird, frog or lizard adds a nice finishing touch. Make sure it is made of resin, stone, or metal so that it doesn’t start rotting or molding over.
If it is necessary to further moisten the container, you may use a turkey baster to add just a bit of water around the edges of the container. After planting, you’ll need to observe the container closely until you can tell if the plant is too wet or too dry. If the sides of the container produce too much condensation, you may wish to blot some of the moisture, although a certain amount of condensation is normal, especially during the warmest and coolest parts of the day. Paper towels are great for this job. If you have over-watered a plant you might even take it out of the container and set it on several paper towels. Terrariums are very forgiving, so don’t be afraid to remove and add plants as you find the perfect balance.
Useful Stuff to Know About Feeding Birds
Black-capped Chickadee: courtesy of Aspen Song
Northern Cardinal: courtesy of Aspen Song
Location. Location. Location. Hang your feeder in the quiet place near trees and shrubs that provide protective cover. Cats are cute, but not to birds, so don’t hang your feeder too close to the ground. On the other hand, don’t hang the feeder 15 feet high or higher - birds natural feeding habits are about eye-level (5-8 feet) similar to a shrub height or small tree height. Finally, don’t place the feeder too close to windows – birds can easily be scared away by your indoor movements.
Avoid cheap seed mixes. They’re inexpensive because they’re packed with a high percentage of millet, cracked corn, and other fillers that native songbirds do not like. Worse yet, cheap seed attracts those infuriating invasive sparrows that overwhelm your feeding area. Millet also attracts large nuisance birds like blackbirds, grackles and starlings.
Dirty feeders can still make birds sick. Empty your feeder and wash the inside in a light (9:1) water-bleach solution. Rinse thoroughly and allow to air dry. Remember to do it every month or so. If you have NEVER done this, do it today. Also keep in mind that seed, like any other food, goes bad. Last year’s seed is probably not healthy. If your seed is full of cobwebs, flour moths have invaded it. Yuck!
Go easy on the stale bread. Birds may seem to love it, but bread to a hungry bird is like popcorn is to a hungry human: Loads of filler, but no nutritional value. Bread also attracts mostly starlings and house sparrows.
Provide suet. It replenishes energy and nutrients, and helps birds survive the long, cold winter. In the spring, suet meets the increased energy demands of nesting birds. In the summer months, it provides a good substitute for insect-eating birds, especially in years when insects are not very plentiful. In fall, suet helps wild birds store fat to prepare for migration or the coming winter.
New feeders may require patience. Depending on your environment it can take birds days, weeks, and in some cases months to start to use a new feeder. If the feeder is a replacement from an older feeder, it may still take time for them to use the new feeder.
Give them a drink. A heated birdbath in winter provides a reliable source of water, and gives birds more reason to stay in your location. Sporadic visits. Birds generally feed 3 times per day: morning, midday, and early evening. Don’t be surprised if the rest of the day your feeder is quiet. Birds can also be highly active one day and vanish the next. Don’t be alarmed, chances are they will return.
Place the feeder where you can watch. Use binoculars and keep a bird guide handy. Watching birds is not only fun, you’ll be reminded when the feeder is empty. Best of all watching birds lowers your blood pressure. (OK we made that last bit up – but who knows, it might.)
Winter Damage
What winter damage is, and what to do right now to prevent it
Winter Damaged Rhododendron
Now that winter seems to be really here, it’s a good time to address the most common cause of winter damage to shrubs: wind and sun. Did you think it was cold and snow? A lot of people do, but that is a misconception. In fact snow acts as an insulator and protects plants. The real damage happens when winter wind and sun draw moisture out of plants and, because the ground is frozen, the plant’s roots cannot replace the lost moisture. Common examples of winter damage are browning of leafs, dead rhododendron flower buds, dead branches and in sever cases loss of the entire plant. Broadleaf evergreens are most vulnerable – especially Rhododendrons, Azaleas, Holly, Boxwood, Andromeda, and Mountain Laurel. To a lesser degree needled evergreens such as Arborvitae, Cypress, Alberta Spruce and Yews are also vulnerable. For the most part, deciduous plants (those that lose their leaves each fall) do not suffer winter dehydration (desiccation).
Wilt Stop: Wilt-stop is an anti-desiccant, an all natural spray that coats the greens with a thin wax that helps prevent moisture from evaporating from the needles and leaves
Two preventions that work:
Spray with an anti-desiccant
Right now - literally this weekend, when temperatures are 40 degrees or above - spray your broadleaf and needled evergreens with an anti-desiccant. The product we like best is called Wilt Stop. Spray it on the upper and lower leaf surfaces and it will provide an invisible waxy coating that will seal in moisture, protecting the plant from the drying winter winds that can cause browning, desiccation and death. This is particularly important for newly planted shrubs, container plantings, and any evergreen that is planted in an area where it is exposed to strong winter sun or wind.
Wrap with burlap
Newly planted evergreens, and those that are planted in exposed, windy areas may benefit from being wrapped in burlap for the winter. The best way to do this is to drive 3 or 4 stakes into the ground around the plant, wrap the burlap around the stakes, and staple or tie securely. If you want to protect an evergreen hedge, you can simply drive the stakes into the ground every 3 feet or so on both sides of the hedge and staple the burlap to the stakes, snug against the hedge, rather than wrap each plant individually. Evergreen hedges planted along the street may be exposed to road salt so it’s best to use a double layer of burlap for greater protection. Road salt can be very damaging to the foliage. Never use any type of plastic, as this material will heat up on sunny days, causing the foliage to burn.
Special note about Hydrangeas
Hydrangeas are also susceptible to desiccation. Flower buds that are located on the canes can also suffer winter damage. In this case, sprays and burlap are not the solution. Instead gently stuff straw or leaves in the middle of the canes, then tie up the canes and mound more straw or leaves around the outside. This cocoon should protect next years flowers from this winter’s wind and sun. Final note: do not uncover too early in the spring as tender buds could still be damaged during spring frosts.
Jean Dooley, Commercial Account Manager
How to Feed Annuals
Did you know that at Mahoney’s our garden hose water has fertilizer mixed in? That means every time we water our annuals we’re feeding them. If you want your annuals to continue to look their best it’s important to continue to feed them at home. Not surprising, if you search online for fertilizing instructions you’ll read a lot of high maintenance, often conflicting instructions. That’s why we thought we’d try to simplify the issue.
To start, here are two quick facts to keep in mind
- Water alone is not enough; annuals need to be fertilized. Some annuals such as Geraniums and Petunias need higher amounts; other annuals such as Impatiens and Scaevola need less.
- If your annuals are in a container or hanging basket every time you water without adding fertilizer, or whenever it rains, water drains through the hole at the bottom of the container, and nutrients in the soil are carried along with it. These nutrients need to be replaced.
There are 2 basic fertilizers: water-soluble and time-release granular – both work well, and using the two in combination often works best. (Note: the following are instructions only for annual plants – perennials, shrubs, etc have different feeding needs)
Water-Soluble
Water Foluble Plant Food: Miracle-Gro All Purpose Plant Food 20-20-20Our best-selling water-soluble fertilizer is Miracle-Gro All Purpose Plant Food 20-20-20. It’s fast acting for both indoor and outdoor plants, and has a unique ability to be absorbed through both roots and leaves. (Note: there are many water-soluble fertilizers on the market, but Miracle-Gro 20-20-20 is only available at independent garden centers.) Feeding with Miracle-Gro is pretty easy; you can use their Hose-end Garden Feeder‚ or simply mix it in any watering can. The instructions on the package say to mix 1 tablespoon of Miracle-Gro for every gallon of water, and to feed every 7 to 14 days. But because nutrients are so frequently leached from the soil, we actually recommend feeding every time you water – but at a lower concentration – approximately half the dosage.
Time-Release
Time-Release Plant Food: Osmocote Outdoor and Indoor Plant FoodThe time-release fertilizer we recommend is Osmocote Indoor and Outdoor Plant Food – it’s super easy to use and feeds for months. Simply spread the granular fertilizers over the soil around the plants and scratch them in lightly. Then water. Apply at planting time and then once or twice over the growing season.
Using Both
In our experience we get the best results when we use both methods in tandem. We recommend a handful of Osmocote when you first buy the plant and then dilute applications of Miracle-Gro every time you water
Too much of a good thing
While we recommend frequent fertilization, “over-fertilizing” is a bad thing. Overly rapid, weak growth is often the first sign of too much fertilizer. More insidious is “root burn.” This is where the too much fertilizer causes the roots to shrivel and die. The plant will appear as if it hasn’t received enough water, but that is erroneous. The water was there, but the roots were not able to take it in. In either case, immediately cut back on fertilizer and allow the plant a chance to return to a normal balance. We also suggest you do not fertilize very dry plants. Dry roots can be sensitive to the salts in the fertilizer – another good reason to have the slow-release fertilizer in place.
Final note
Don’t be afraid to prune. Annuals actually perform better when occasionally pruned back – especially if you see unshapely, leggy growth. There is no special skill required – simply take your trusty pruners (or sharp scissors) and cut back a little to create a more dense, rounder shape. Keep in mind that well-fed plants tend to grow quickly and will require more trimming.
How to Plant a Mixed Container
If you are new to making container gardens, it’s easy to feel intimidated. So, specifically for beginners, we’ve simplified the plant selection part: Choose 3 different plants: one for “height” another for “spill” and the third for “fill”. It’s also a good idea to select plants that have similar light and water requirements. My suggestion is to come in (ideally on a weekday when the place is a little less busy) and have one of our staff help you select plants with similar growing habits. We have lots to choose from. To this simple example, we’ve selected one Dracena for height, one pot of Algerian Ivy for spill, and one pot of pink Impatiens for fill.
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Select Your PotTake into consideration the size of your plants as they matures – it’s fine to plant close side to side, but allow plenty of room for the roots to grow down. The pot shown here is a plastic pot made in Italy by Marchioro. Marchioro have has a nice drainage feature (explained step 5) but ceramic, terra cotta, iron, fiberglass containers are all good choices.
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DrainageWhen roots are allowed to sit in water they form “root rot”. To avoid root rot, choose a container with drainage holes, or a container that allows you to add holes.
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GravelAnother way to prevent roots from drowning is to add a few inches of loose gravel. The gravel prevents the roots from sitting in excess water. Marchioro containers have a smart design: their drainage holes are elevated from the bottom of the container – excess water is held in reserve and made available to the plant later – basically a timed-release self watering container.
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Choose a Potting MixAlways start with a good quality potting soil – never garden soil. We’re partial to our Mahoney’s Professional Potting Mix which we formulated to have the right blend of peat moss, vermiculite, perlite, and starter nutrients.
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Potting Mix DepthMost likely you will be planting different size plants with different size root system. Start by adding enough mix so that when you place in the biggest plant, the top of the soil is about 1 inch below the rim.
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Preparing RootsBefore planting, gently remove each plant from its plastic pot and “massage” the roots to loosen them from their compacted pot shape. The goal is to allow the roots freedom to grow wide and deep. Then place the plant in the container. We’re placing the Dracena (height) in the center because we will use “spill” and “fill” on all sides.
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More MixAdd more mix so that the top of the root ball of the spill plants also sits 1-inch below the container rim.
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Divide SpillerRemove the Algerian Ivy from its pot and gentle divide the root ball into two halves.
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Planting the SpillPlace one half in one corner, and the other half in the opposite corner.
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The FillRemove the Impatiens from its pot. We used a pretty big 8” container, so this time we’re dividing the plant into four.
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Planting FillPlace each quarter root ball so that the Dracena is equally surrounded.
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Checking balanceLook at the container from all sides to make sure there are no empty areas.
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One more time add mixGently press in more mix to ensure the roots are firmly surrounded by mix. Make sure to leave about 1’ of space below the rim to prevent water from spilling over the edges.
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Add Slow release fertilizerFor the best flowering performance, “top-dress” the plants with a handful of Osmocote slow-release fertilizer.
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Osmocote will get absorbed by the plant a little at a time whenever you water.
What to do with your dead leaves
This time of year you see a lot of “eco-friendly” gardening advice about dead leaves and I wholeheartedly endorse the bottom line - that it’s crazy
to send them off to the local landfill, where they take up space and waste all that organic matter. But the next part of the advice - what to do with them instead - well, that’s where it starts to get complicated but hey, that’s gardening! Let’s dig in.
On the lawn
Nobody seems to think that whole leaves should be allowed to remain on lawn because they can smother turfgrass. Many experts suggest instead that we run over them with a lawn mower and let the chopped-up leaves stay there as a source of organic matter and some nutrients for the turfgrass. That’s great advice and don’t worry - it won’t cause or contribute to a thatch problem. (Thatch is usually caused by overfertilization with synthetic fertilizers). Some brand new research proves that chopped leaves not only add organic matter and nutrients – they even suppress weeds! Here’s the story.
However, some folks consider any use of a gas- or electric-powered lawn mowers to be an unsustainable gardening practice for obvious reasons - the fossil fuels involved (either gas or the coal required to produce electricity). But lawn mowers are a topic for another time - a very hot topic these days. So moving on, if you do remove leaves from your lawn or anywhere else, what do you do with them? See composting below.
In the vegetable garden
This situation is a simple one. Leaves that fall on an emptied vegetable garden can be left in place and then turned under in the spring, after which they’ll decompose quickly, adding organic matter and some nutrients to the soil.
On hard surfaces
For obvious safety purposes, dead leaves should be removed early and often from surfaces people walk on. And certainly all wood surfaces benefit from having the leaves removed to prevent rotting.
In the flower and shrub beds
What to do about leaves on and around our ornamental beds and borders is where the hot-under-the-collar arguments really take place. (Yes, gardeners are an opinionated bunch.) Though everyone does agree that chopped leaves are great in the beds and borders as an organic mulch, and for more about chopped-leaf mulch, check the Illinois Extension Service.)
But whole leaves? Well, it depends - on how many leaves, what type of leaf, and which groundcovers those leaves are covering. To get personal, about 50 trees drop their leaves on my garden, most of them large oaks, and these masses of large, whole leaves can mat down and smother my groundcovers, or at least create a barrier that would prevent rainwater from seeping through to the soil. And oak leaves simply don’t decompose over the course of the winter, so I’d have to collect them in the spring anyway, so why not do it now? I rake up about 80-90 percent of them in December when they’ve all fallen, and I do the fine-raking and hand-picking in the spring when I’m cleaning up, mulching and generally prettying up for the new season.
But not everyone agrees about this. Syndicated columnist and Maine gardener Barbara Damrosch writes that “Most ground covers…benefit from a weed-smothering leaf mulch - once winter has matted it down a bit - and will come up happily in spring. I let leaves collect in perennial flower beds, too, removing them carefully with a narrow, springy metal rake just before spring bulbs poke up. They can be gathered for the compost pile.” But Barbara, how come they smother just the weeds and not the desirable plants, your groundcovers? Could be that your groundcovers are unkillable, like English ivy and Pachysandra, while I’m talking about more delicate ones like Pulmonaria and Ajuga?
So here’s where I come down: If you have just a few leaves, or if they’re thin like elm leaves, then they probably won’t do any harm and will decompose by spring, so go for it - if you like the look. Yes, appearance, pure aesthetics and nothing more - is another reason I remove most leaves in the fall - because I’d rather see even semi-evergreen groundcovers than brown, dead leaves. Gardeners in colder climates may be looking at snow cover from Thanksgiving until May, so they laugh at the very notion of seeing their groundcovers over the winter.
See how many variables are at play here? And why it drives me crazy to see gardening advice that assumes all gardens are the same!?
Composting dead leaves
Now if you DO remove any or all of your leaves, what should you do with them? Everyone agrees that they make for some mighty fine homemade compost, especially if you combine them with some green matter like lawn clippings for a nutritionally complete result. But there’s disagreement about whether whole leaves compost well and here I’ll weigh in. My compost method (such as it is) is to simply pile the leaves up and wait a year or more for them to decompose. The problem is they never DO decompose completely because I never water or turn the pile. (Breaking all rules, I know, but turning is hard work.) But no matter – I use the resulting so-so “compost”, containing some noticeably uncomposted chunks, in out-of-the-way spots as mulch, or to amend the soil.
But if you want to turn dead leaves into quality compost it’s much better to chop the leaves first, and I did that for a whole season a few years back. I bought a cheap filiment-style shredder for about 100 bucks and ran all my leaves through it. But because it was a cheap, flimsy machine, the Weedwacker-type filament broke with every twig and acorn it encountered, so every five minutes or so I had to stop and replace the filament, and the chopping process became a super headache. If I’d spent more on a chipper-shredder the work would have gone quickly, but I judged $1,000+ to be too steep a price for faster, more uniform compost. Of course I could have spread all the leaves on the lawn, then mowed them with a mulching mower (one with a bag to catch the cuttings) but that sounds to me like a whole lot of work to me.
The Rutgers Extension Service has good information about composting with dead leaves - check that link. They offer a tip I hadn’t seen before - adding Nitrogen to the compost bin to speed up the process.
If you don’t have space for a composting operation, your city or county may have the answer - or will soon if enough residents ask for it. About 20 years ago local governments across the U.S. began prohibiting the dumping of green waste like leaves and creating programs to collect and compost yard waste for their residents. As a result, they make good use of all that organic matter, save the money they used to spend on landfill fees, and save even more money because they’re using their own homemade compost on public land instead of buying compost and fertilizer products.
Below you see the city crew picking up leaves on my street, and the resulting mulch pile delivered to my driveway the following spring. 
My Turn - Planting a river of bulbs
Bulb planting is an act of faith. Faith that a small, round, dormant piece of plant tissue that’s a modified stem, will, when planted, rest, relax and wait until the conditions of spring activate its urge to grow into a flowering plant. Really, a bulb is ingenious. The entire plant is contained within a bulb, a fact that’s perhaps easier to accept than the notion that tiny seeds contain the necessary ingredients for full plants. It does take a bit more effort to actually plant a bulb than a seed since bulbs need to be planted at a depth proportional to their size. In the case of daffodils and tulips, that will necessitate digging a hole about six inches deep.
There are many ways to plant bulbs and as long as they’re planted at the correct depth, the only wrong way to plant them is in a straight line. Many of us have learned this lesson the hard way - that is, spending all the time and muscle required and having the spring bloom look weak and staggered because there are just not enough bulbs in one area to make an impact. Susan has outlined her clump method of planting bulbs here, and I find it to be very effective when you want to coordinate colors in the border or if you just want a punch of color. But there are a couple other ways to achieve a successful and pleasing planting. One is to naturalize bulbs. This was done at Tower Hill Botanical Garden where thousands of daffodil bulbs are planted in the field to great effect.
Many of us don’t have the equipment or room in either our gardens or wallets for this method of planting. It does look gorgeous though doesn’t it?
Another method for planting a volume of bulbs, 50 to 100 or more, is to plant a river. Consider that an undulating river, drift, or ribbon of color running through the garden can be done with as few as 50 bulbs. That’s a rather short ribbon and most gardens, even small gardens, can handle a couple hundred bulbs. As you can see, this is a large border and a natural border against a stone wall. Though not close to the house, it can still be seen easily especially because there are so many bulbs in one area - masses show up much better than spots of color.
As to the method of planting, those bulb planters, either the short or long handled variety, just don’t get this job done and are much harder on wrists and hands than a long handled shovel. My rocky patch requires the presence and use of a pick axe, which you see here lying on the ground in the above picture, but don’t let that scare you. Using the correct tool for the job will actually save you energy. I had my doubts but the proof is in the planting. Idug this river initially in 2007 when I planted the first hundred daffodils, along with about 50 species tulips. They’re the pink cupped narcissus, ‘Accent’.
I learned a lesson from this planting. The pink cupped are beautiful but they don’t show up from a distance as well as the bright yellow daffodils do. I extended the river in 2008 with the yellow variety you see here.
I included large tulips in the bed with the realization that tulips are short-lived, but daffodils will bloom for many years after planting and have the added advantage that critters don’t find them tasty. They’re an investment.
I’ll add that planting such a large mass of bulbs means that the dead and dying foliage should be considered since it can’t be removed or the next season’s bloom will be compromised. I’ve added daylilies in front of the river to hide the dying foliage of the daffs. It’s a good companion planting and gives you yet another drift of color in the summer. What method of bulb planting do you employ and are they in the ground yet? It ‘s time.
Planting Daffodils and Saving Time
I’m embarrassed to tell you how I used to plant daffodils - one at a time, all spaced about a foot apart. Here’s what’s wrong with that approach:
- To state the obvious, to get hundreds of daffs in the ground meant digging hundreds of 8-inch-deep holes. Lots of work, lots of time involved.
- And not quite so obvious is the rather boring-looking result. Boring and unnatural - because plants never grow evenly spaced like that. Not coincidentally, what looks best to our eyes is usually what mimics (but improves on) the way plants grow in nature.
So, here’s technique I’m using these days - planting 3-8 bulbs per hole for a nice little clump, and a lot less work for this aging gardener.





