Impatiens provide vibrant, long-lasting color, even in shady areas of the garden.
I always have these annuals either under my apple trees, in pots on the patio, or even indoors as houseplants.
But every now and then, the plants don’t perform as well as they could. Instead of putting out heaps and heaps of blooms in all kinds of colors, they might not flower at all.
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If you’re not seeing flowers on your impatiens plants, it’s time to go into detective mode and figure out what’s going on.
In my case, it’s usually as a result of something silly I’ve done like putting the plants in too much shade or maybe I forgot to water the pots that I’d put on my back patio.
However, sometimes the cause can be harder to determine. It may be a problem caused by pests, disease, or even too much fertilizer.
In this guide we’re going to discuss seven common reasons why your impatiens may fail to bloom and what, if anything, you can do about it.
Here’s what I’ll cover:
7 Causes of Impatiens Not Flowering
1. Disease
Impatiens necrotic spot virus (INSV) can cause all kinds of strange symptoms, including stunted growth or a lack of flowers.
The virus is spread by thrips and can also result in symptoms like wilting, weird spots or stripes on the leaves, or dying leaves and stems.
Downy mildew is another common disease in these plants. Growers are trying to breed resistant cultivars since it has become such a problem.
Unfortunately there is no cure if a plant is infected.
Symptoms include silvery-white mold on the foliage, stunted growth, and – you guessed it – no flowers.
Learn more about both of these in our guide to growing impatiens.
2. Heat Stress
Impatiens plants don’t like extremely hot weather, especially combined with dry soil.
A day or two of temperatures above 85°F won’t stop flowering, but extended hot periods can result in heat stress, which stops flowers from forming.
Until we figure out how to control the climate in our gardens, there’s not much you can do to change the weather.
If your plants are growing in pots, you can try moving them to a cooler, shadier spot. Or you can erect some sort of shade like umbrellas or shade cloth.
During heatwaves it’s essential to keep your plants well-watered and they should start blooming again when the temperatures drop down a bit.
3. Light Issues
Though they like the shade, these plants don’t want deep, full, vampire attracting, anglerfish-quality, Darth Maul side of the force dark.
A little dappled light or even direct sunlight in the morning is ideal, and some species and hybrids actually want a bit more light than that.
New Guinea impatiens (I. hawkeri) need more light than garden varieties (I. walleriana), which require at least a few hours of dappled sunlight, and any of the SunPatiens® series (I. x hybrida) can tolerate full sun.
For the best chance of full flowering, give New Guinea impatiens full sun in cooler climates and partial sun to partial shade in hotter regions.
Avoid direct sun in the heat of the day if you live in a hot region.
Garden impatiens do best with morning light and some dappled sunlight throughout the day, though they can get by with a bit less. SunPatiens® do well in full sun or afternoon shade.
4. Low Temperatures
Regardless of the species, impatiens do best when temperatures are in the mid 60s to 80s.
As temperatures start to drop lower than the low 60s, they will stop flowering.
You might find hybrids or cultivars that are bred to tolerate slightly lower temperatures, but assume that once it’s in the 50s in your area, it’s unlikely that your plants will bloom.
5. Moisture Issues
These plants like a good amount of water, the soil should be kept consistently moist at all times.
If it’s allowed to dry out too often, this can stress the plants, causing them not to flower.
Plus lack of moisture can lead to reduced growth, wilting, and leave the plant susceptible to other issues like pests and diseases.
On the other hand, soil that is consistently too wet will drown the roots. You’ll probably see soggy, brown leaves and stems in addition to the lack of flowers.
In either case, you’re aiming for the soil to feel like a well wrung-out sponge. If it feels soggier, the soil is too wet, and if it feels drier, the soil is too dry.
A good inch of straw, leaf litter, or shredded bark mulch around the plants, but not touching the stems, can help regulate the soil moisture.
6. Overfertilizing
You know the saying “too much of a good thing?”
That definitely applies when it comes to fertilizing plants. If you overfertilize, the plant often becomes bushy and full of foliage at the expense of flowering.
Before you fertilize, it’s always a good idea to do a soil test. This applies to those growing in containers as well.
If you planted in fresh potting soil, assume that the plants don’t need feeding for the first year. But older soils should be tested. Tests are cheap and well worth the cost.
To test your soil, you can reach out to your local university extension office. They’ll have recommendations for local testing companies.
Or you can purchase a test kit online that will provide a detailed analysis of your soil and recommendations for how to amend it.
After testing your soil, you’ll know whether you need to fertilize or not and what product to use.
7. Pests
Sap-sucking insects like aphids, spider mites, and thrips will all feed on impatiens, causing stunted growth plus lack of flowering.
Examine the plants closely to look for the pests themselves or signs of feeding.
Beyond the lack of blooms and stunted growth, you might see yellow stippling or fine webbing on the foliage.
If you see evidence of pests, you can use a spinosad-based product to deal with any of the aforementioned sapsuckers.
Bonide Captain Jack’s Deadbug Brew
Pick up Captain Jack’s Deadbug Brew at Arbico Organics.
Bring Back the Color
I can’t help but smile when I see a cheery patch of impatiens. But a mound of greens that refuses to bloom? That’s a quick way to make me frown.
Were you able to figure out what’s causing your impatiens problems? If you’re still having trouble, pop a description and a few photos into the comments section below and we’ll see what we can do to help you out.
And for more information about how to grow impatiens in your garden, check out these guides next:
help
its getting warm here in south Florida but i have my beauties getting only about 3 hours of morning sun. they should be doing well but the flower buds wither and die before flowering. i cant figure out why
Hm, hard to say without more information. Could you send any images? Do the flower buds drop off before opening or do they start to open and then wilt and drop? Are there any symptoms on the leaves? It sounds like they receive enough light, but it could be any number of other causes.