A Gardeners Forum Forums General Discussion Plant pests and problems Yellowing Impatiens

About 5 weeks ago we planted impatiens in the flower beds in the front yard. The plants have not grown at all and in the last week the leaves are turning yellow.

I don't have a lot of experience growing impatiens. Actually most of my previous attempts to grow them have failed.

The plants get a mix of sun and shade - mostly morning sun. In the last month we have had a lot of rain in our area so it has not been a lack of water.

I am wondering if the mulch we put in the beds is affecting the plants. We bought "natural" mulch from Lowes that had been shredded locally.

Any ideas?

Is the mulch right up against the plants? don't mark my words, but I think the mulch should not be right up against them and the plants should be given about an inch around its base. The mulch might lock water against the plant and cause the stem to rot.

Yellowing leaves should like there isn't enough nutrients (particularly nitrogen). Nitrogen is needed to help the plants grow leaves, and as things decompose (mulch included), it can actually take up nitrogen from the soil. The mulch (once it becomes decomposed) will then release nitrogen back into the soil.

I think kennyso hit the nail on the head...the shredded mulch is robbing the impatiens of nitrogen. You cannot overwater impatiens, so fertilize a couple of times with half strength liquid fertilizer within one week or 10 days and see if you get greening. Continue to use Miracle Grow or your choice of fert weekly for 3 to 4 weeks, then switch to BR63 or a high phosphorous fert. if the plants show good, green growth, and you'll be amazed how many blossoms you get.

While the mulch-decomposition-nitrogen hypothesis is reasonable, I'd also wonder about the quality of the soil, and what's in the neighborhood of the flower bed. Even finely shredded mulch takes a while to get cranking & breakdown, and in my experience 5 weeks isn't long enough to rob all of the underlying soil of it's nutrients. Plus, if you've tried impatience in the same place each time, that suggests there's something else going on.

What's the soil like? Is it loamy, or clay or sandy? If you go out there and stick your finger about an inch into it, is it moist? Can you even get your finger through it (you should be able to under the mulch if the soil is nice & loamy). Are there other shrubs or trees nearby? Some will have a root mat that's very close to the surface and these could just be sucking up the available water, and prohibiting rain from soaking into the soil.

Again, I like the hypothesis (and this is why I don't use shredded mulch) but I think there's more to investigate here. Can you post some pics of the plants & the soil?

Some good points, Marica...for sure, if the soil is compacted or clay, impatiens won't thrive. If it's somewhat loose, fertilizing might solve the problem, and I'll repeat that you can't overwater impatiens, so don't hold off...I've seen inpatiens thrive in a half-barrel with no drainage, with water an inch deep above soil level! Impatiens are fairly forgiving, you could add more soil where they are (if the soil isn't too dense) and even bury the stems one to 2 inches. I'm convinced you have a nutrient deficiency, whether it's the soil not giving up nutrients (clay or pH problems) or a simple lack of nutrients in otherwise decent textured soil.
Let me add, some shredded mulch is fine...I like cedar or cypress mulch, some areas have aged oak or other wood mulch, but some woods are more nitrogen robbing than others. I can't say I've seen problems with surface applications, but that's an issue that's frequently discussed on gardening programs and magazines...I did ruin one garden area for about 5 years by tilling in a large amount of pine sawdust...I thought sawdust would break down rapidly, silly me, the soil was basically worthless, the sawdust took forever to break down...tilling it in utterly robbed the soil of fertility.