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An important message about Downy Mildew, a disease effecting Impatiens

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Example of Downy Mildew Sporulation on the underside of an Impatiens Leaf

One of the most popular annuals to plant each spring are Impatiens. For many, it’s a tradition to give a basket of Impatiens as a Mother’s Day gift, while for others it is the easiest way to enjoy color in their gardens all summer – even in the shade. If you grew impatiens last year you may have noticed that they got black spots and turned yellow. Most likely it was not your fault, nor was it the fault of the retailer or even the grower. Impatiens walleriana, the common impatiens and number one selling annual in America today, are the victims of a new nationwide disease called Downy Mildew.

Impatiens infected with Downy MildewImpatiens infected with Downy Mildew

Here’s some important information:

  • Only Impatiens walleriana and Rosebud Impatiens are prone to Downy Mildew. The New Guinea Impatiens and other plants are not at risk.
  • Downy Mildew resides in the soil, but the spores are air borne. If your neighbor’s plants become diseased, it’s likely your Impatiens will, too.
  • Impatiens grown in hanging baskets are less likely to get this disease.
  • You can attempt to prevent the disease with a fungicide such as Neem or Copper sprays, but once a plant is infected, there is no known cure.
  • To reduce the likelihood of disease, provide good air circulation & don’t overcrowd your impatiens. Try not to get the leaves wet when watering, water from below and early in the day.
  • If any impatiens shows signs of the disease immediately remove it – dirt and all. Do not compost any of it, the plant and soil are now diseased.
  • Mahoney’s grow our own Impatiens locally under careful scrutiny, all have been treated – however this is a very invasive disease – Mahoney’s provides no warranty on Impatiens walleriana.

There are several excellent colorful, shade-loving alternatives that are not affected by Downy Mildew:

New Guinea ImpatiensNew Guinea Impatiens

BegoniasBegonias

CaladiumCaladium

ColeusColeus

My Azaleas and Rhododendrons look dead! What can I do?

Written byUncle Mike Mahoney
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Although the leaves may be brown and curled, this doesn’t necessarily mean the plant is dead. In fact in most cases the plant will rebound easily with a little TLC.Winter Damage on a Rhododendron: Although the leaves may be brown and curled, this doesn’t necessarily mean the plant is dead. In fact in most cases the plant will rebound easily with a little TLC.After a long, cold, snowy winter like we just had, we often see damage to our shrubs and trees often called “winter kill” or “winter damage.” The most common damage is brown or dead-looking azaleas, rhododendrons, holly and other broadleaf evergreens. Most people assume cold temperatures are to blame, but it’s actually caused by dehydration. In winter, cold dry winds and bright sunshine suck moisture from the foliage of broadleaf evergreens, much like chapped lips after a day of skiing. Plus, because the ground is usually frozen and the plant is dormant, plants can’t move water through their roots back to theire leaves. The result is dehydration, browning the tips of leaves or even entire branches. The more exposed to wind and sun, the greater the damage; particularly heartbreaking when it happens to shrubs you’ve loved for 20 years or more. Yes, sometimes the plant is dead and will need to be replaced, but often winter damage only make shrubs appear dead.

How do I know if it can be saved?

Look carefully and you’ll see that the leaves may be brown and brittle but the branch may have good life. Try gently scratching the bark with a fingernail, if underneath it’s greenish and pliable it’s probably still alive. If under the bark is brown and brittle the branch is probably dead – but not necessarily the whole plant. Continue the exploration down the branches and you will probably see some life along the way. Usually I tell people to leave winter damaged shrubs alone until late May. By then you can see the new growth starting, making it easier to see and prune the brittle dead wood. In any case, don’t give up on them to soon – in early spring, winter damage often looks a lot worse than it really is! All you need is a little patience and a good organic fertilizer.

Try gently scratching the bark with a fingernail, if underneath it’s greenish and pliable it’s probably still alive. If under the bark is brown and brittle the branch is probably dead – but not necessarily the whole plant.The Scratch Test: Try gently scratching the bark with a fingernail, if underneath it’s greenish and pliable it’s probably still alive. If under the bark is brown and brittle the branch is probably dead – but not necessarily the whole plant.

Use it on all broadleaf evergreens like Rhododendrons, Azaleas, Holly, Boxwood and Andromeda.Holly-tone by Espoma: Use it on all broadleaf evergreens like Rhododendrons, Azaleas, Holly, Boxwood and Andromeda.

Help the recovery with a good organic fertilizer.

I can remember I had a Holly and an Azalea that turned completely brown from winter damage. Then after feeding with Espoma Holly-tone fertilizer and some warmer weather from Mother Nature both plants completely re-foliated and grew back to where they were the previous fall. This saved me the time and effort of replanting the shrub. The earlier in spring you take action the better because it will allow more time for the bare branches to re-bud and start to fill in. There are other products to choose from, but Holly-tone is easy to use and it’s worked well for me. If there is mulch around the base, just push it away to expose the soil. Scratch the soil surface a little to allow for good soil contact and spread Holly-tone around the drip line of the shrub (the area under all branches). Just follow instructions on bag for proper quantity. Then just replace the mulch, water and wait for the magic healing to begin. You may need to go back and do some tip pruning later to cut out some dead wood but it’s far better than throwing out a live plant.

Side note:

There are several products that help prevent winter kill. They’re called “anti-desiccants,” a kind of a sunscreen for plants. Spraying an anti-desiccant places a harmless transparent wax coating over the broadleaves. The effect is to reduce the dehydration caused by wind and sun. Typically it’s applied after the first really cold nigh in late November or December. At Mahoney’s we recommend Wilt Stop by Bonide, but there are other good products to choose from.

'Uncle' Mike Mahoney - Mahoney’s Garden Centers
Have you’ve seen our herb and vegetable plants and wondered, “Who is Uncle Mike?” Uncle Mike is Michael Mahoney, one of the six second-generation Mahoneys. With a face full of beard and too-well-worn hat, Uncle Mike is a genuine down-to-earth guy. With a passion for vegetable gardening Mike...

Designing with Houseplants Series - 3 - Vani Sayeed

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  Plants Pictured Other Good Choices
Miltonia ‘Pansy’ Orchid Anthurium
Cymbidium Orchid
Heliconia
Croton ‘Zanzibar’ Maidenhair Fern
Philodendron ‘Silver Satin
Aeschynanthus Lipstick Plant
Calathea ‘Roseopicta’ Calathea Lancifolia ‘Rattlesnake’
Aspidistra Variegata

This eclectic shot is the third from a series of photo shoots worked on in the past couple months. We had the pleasure to collaborate with some talented local interior and exterior designers on designing with potted plants. We asked them how they incorporate plants and pottery into their designs and they were happy to indulge us. We’ll be posting one item in the series per week for the next few weeks. We hope you get as much inspiration out of these shots as we did!

Interior Designers like Vani Sayeed know that houseplants add color, texture and life to every room in your home. Plus they naturally help clean the air. Getting started is pretty easy, too. First discover our wide selection of indoor plants – many easy-care and low-light tolerant – and then explore our beautiful decorative containers. For a full explanation of designing with potted plants, visit How to Design with Potted Plants

  Vani Sayeed | Interior Designer
vanisayeedstudios.com

 

Designing with Houseplants Series - 2 - Ana Donohue

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Matt DooleyPhoto Credit: Matt Dooley

  Plants Pictured Other Good Choices
Anthyrium Cordyline
Bromeliad
Oncidium Orchids with Pothos Phalaenopsis or Miltonia Orchids
with Maidenhair Fern
Croton ‘Magnificent’ Aglaonema ‘Lady Valentine’
Zee Zee Plant
Diffenbachia

This colorful shot is the second from a series of photo shoots worked on in the past couple months. We had the pleasure to collaborate with some talented local interior and exterior designers on designing with potted plants. We asked them how they incorporate plants and pottery into their designs and they were happy to indulge us. We’ll be posting one item in the series per week for the next few weeks. We hope you get as much inspiration out of these shots as we did!

Interior Designers like Ana Donohue know that houseplants add color, texture and life to every room in your home. Plus they naturally help clean the air. Getting started is pretty easy, too. First discover our wide selection of indoor plants – many easy-care and low-light tolerant – and then explore our beautiful decorative containers. For a full explanation of designing with potted plants, visit How to Design with Potted Plants

  Ana Donohue | Interior Designer
anadonohueinteriors.com

 

Designing with Houseplants Series - 1 - Katie Rosenfeld

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Michael J. LeePhoto Credit: Michael J. Lee

  Plants Pictured Other Good Choices
Ficus Lyrata
‘Little Fiddle’
Dracaena ‘Lemon Lime’
Bamboo Palm
Rubber Plant ‘Ruby’ or ‘Tineke’
Tiger Fern Philodendron ‘Brasil’
Pothos ‘Pearls and Jade’
Algerian Ivy
Japanese Aralia Alocasia ‘Polly’
Bromeliad

This gorgeous shot is the first from a series of photo shoots worked on in the past couple months. We had the pleasure to collaborate with some talented local interior and exterior designers on designing with potted plants. We asked them how they incorporate plants and pottery into their designs and they were happy to indulge us. We’ll be posting one item in the series per week for the next few weeks. We hope you get as much inspiration out of these shots as we did!