13
May
2013

Reflections On Impatiens

IMP-mainImpatiens is a hard plant to replace. It does its job exceptionally well, with a robust blanket of color, reliable growth, affordable price, fun choice of colors and vigorous growth in the shade. Yes, other plants can be substituted, but they will possess only two or three of the Impatiens’ attributes at the most; nothing delivers the complete package like Impatiens.

This probably explains the strong demand we’ve seen this year. Last season, many gardeners’ Impatiens became infected with downy mildew. Although they might remember the problems they encountered, people are still more apt to focus on all the wonderful spring and summer color that Impatiens provide.

Unfortunately, downy mildew is a problem and it is here to stay. Our best defense against the disease is knowledge and preparation. Commercial clients as well as homeowners will turn to the professionals in the trade for advice, so here is a rundown on the information we have gathered together:

What We Sell

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First, we sell clean Impatiens. This means we treat our Impatiens with commercial-grade fungicides. We rotate among several different types to prevent the fungus from building up a resistance. We also inspect our crops for yellowing leaves, curled tips or the characteristic downy fuzz on the undersides of the leaves.

Now, all fungicides have a weakness: they wash off with water and the rain. This means any effective armor the plants have in place will last a week or two, at best, after delivery.

What You Need To Do

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Inspect the Impatiens upon delivery, before you move them in with your other material. Once you accept delivery, the responsibility belongs to you. If you discover any infection, destroy the offending plant immediately by placing it in a plastic bag—tightly tied off, so you won’t spread any spores around the property.

Destroy all the plants immediately surrounding the infected plants, too, because they will probably be covered with the spores as well. Vigilance is important, because the spores float in on the wind.

Advice to the Customer

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A little education goes a long way. To prevent the disease, drip irrigation is best, followed by soaker hoses. Watering in the morning is better because it allows the plants to dry off before the evening. Do not allow them to get cold and wet because damp and clammy conditions encourage the fungus.

Once a garden bed has been hit with downy mildew, a thorough cleaning of the bed is important. Downy mildew spores can overwinter in garden debris. The following year, plant something other than Impatiens to prevent a re-infection from the soil.

Alternatives and Replacements

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We recommend New Guinea Impatiens and Sun Impatiens for homeowners; downy mildew only affects the wallerina species, so these two are safe. Both plants are showy and offer the most impatiens-like qualities, but they do cost more.

Another plant to consider is the Vinca. It has a similar flower but a different leaf and habit. For commercial applications, Vincas make more sense as far as price, coverage and durability, until it comes to shade; then it’s necessary to switch to a plant that flourishes in full shade, like the Coleus.

While Coleus likes the shade, is affordable and comes in a ton of colors and patterns, there is no way you can call a Coleus garden an impatiens-style garden.

If indestructible is what you need, then go with Wax Begonias. Although the choices are limited compared to Impatiens or Vincas, you know the Begonias will still be there when you come back, looking great.

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Diefenbacher Greenhouses is a supplier of annuals and creative green goods. We sell directly to Garden Centers and Landscapers in the Cincinnati Area. 

We are wholesale only!

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