How to Feed Annuals

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

  1. 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.
  2. 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 Foluble Plant Food: Miracle-Gro All Purpose Plant Food 20-20-20Water 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 Plant Food: Osmocote Outdoor and Indoor Plant FoodTime-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.

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