Problems affecting Impatiens

I recently found out that there are a number of very serious problems affecting the beloved shade-tolerant annual Impatiens. The 2 most serious are Downy Mildew and a virus called Impatiens Necrotic Spot Virus.

Impatiens Necrotic Spot Virus is not very well understood yet. It is believed to be caused by a small bug called a thrip (also called a thunderfly, storm bug, corn fly or corn lice). The thrip is a very tiny cigar-shaped insect with fringed wings.
The virus causes wilting, stem death, yellowing, poor flowering, sunken spots and/or ring spots on the leaves. But many times the plant dies without showing any symptoms at all.

Downy Mildew causes the same type of damage. Within several weeks of planting, a bout of humid or wet weather can cause perfectly healthy impatiens to suddenly lose all their flowers and leaves and be bare stalks overnight.

Many green houses in the USA have stopped growing and selling impatiens or at least have cut back by 75%.

Last summer this problem starting appearing more often in Canadian gardens.

This is a real shame. Impatiens have long been the most reliable colour annual for shady areas.

What now?

Well, no one is saying not to plant impatiens. The reports are just warning what could happen.
New Guinea Impatiens/Sunshine Impatiens do not succumb to this problem at all.

If you decide not to plant impatiens, here are some good alternatives:

Fibrous or wax begonias were my top performers last summer. Great for sun or shade.

Another wonderful substitute is Tuberous or Rex Begonia. These are gorgeous but quite a bit more expensive.

Coleus has made amazing strides these past years. They now come in a wide array of colours, textures and sizes. They perform best with a bit of shade or in full shade.

Caladium is an indoor plant but I have had much success with its gorgeous pink speckled leaves in shade containers.

Heuchera is another plant that has evolved a lot in the past years. It is a perennial, therefore will cost more up front, but it comes back year after year, so it will pay off in the long run. The reason I mention it as a replacement for impatiens is that it also comes in many multi-colours and stays lovely the whole summer.

Brunnera is another speckle leaf perennial that looks great all summer long.

Variegated Hosta can also add punch to a summer border. Not as much colour as impatiens, but a strong choice to replace the poor little sickly standard.

Please check out my food blog - the latest post is Roasted Chicken Thighs with Potatoes.

Gone Walkabout

In one of my favourite films, Sue comes looking for Mick "Crocodile" Dundee. The doorman says he's "gone walkabout". For Australian aborigines, this usually means a period of time spent walking in the bush. For me today it meant "a walking trip" around my garden.

I decided to walk in the front, side and back, take photos of my late summer garden and make notes as to what worked, what didn't and how to improve plantings for next year.

Note: Allyssum like cool, moist conditions - not high heat and humidity. Do NOT grow from seed anymore.

Note: the true workhorse of the summer was red tuberous begonias. Buy flats and flats of these as annuals next summer. Make it the only annual front and back.

Note: Balloon flowers will re-bloom if deadheaded.

Note: After cutting down Elaine bed, check if the wasps were ground digger wasps and if yes, destroy nests.

Note: this fall or next spring, chain-saw the pussywillows.

Note: Skip the tomatoes and plant herbs in raised beds instead.

Note: Prune bottom branches of walnut tree so that they don't hang into and obscure the Feather Reed Grass

Note: prune Fairy Rose and remove purple Harebell to give the emerging Quince bush more room to grow

Note: move new Carpet Rose and 2 Lavender plants into sunnier spots

Note: Stake Miscanthus grass early in summer using strong metal stakes and wire, not string.

OK - notes have been taken and recorded! Now to enjoy these last summer blooms before I start the huge job of cutting down the garden in mid-October.

Please check my food blog - the latest recipe is Asparagus, Goat Cheese and Bacon Tart.