Expert: C.L. Fornari - 9/19/2010

Question
I have been planting varigated impatiens inside for quite a few years. This year the blossoms appear and tnen drop off before they open up, I have given many away and they are beautiful outside. Mine gets sun from the east in the room that I grow them in. Even have had them all winter and they were beautiful. What is my problem? Soil was saved outside for the winter.

Answer
Violet,
Hopefully I'm understanding what you're saying, and if not, let me know, OK? I think that you're telling me that you've grown these variegated impatiens inside for years, and they've done well, but this year the flowers drop off before they open.

I'm assuming that these are the same plants that you've always had, yes? Not new ones grown from seed you've had or new plants grown from cuttings you've taken?

In general, plants will drop buds when the plant is stressed in some way. this could be if the soil dries up between watering, or if it's too wet, or if the plants get fertilized when soil is dry, or with a too high concentration of fertilizer.

I'd ask if you've used the same soil for a couple of years - if so, it might be nutrient poor or the organic matter in that potting mix might have broken down to the point where it doesn't contain the same air pockets as in the past so it's less conducive to good root growth. Such soils can retain too much moisture or not have enough nutrients to support the growth of the plants.

If the soil has been in the same boxes or pots for a couple of years it can also contain the old roots and not be as fertile or have the air it needs. Sometimes the drainage holes are clogged with the old roots and the soil is no longer draining well.

In general, it's good to take old potting soil and refresh it with some new potting mix and/or some compost and pieces of bark. Mixing this all well, and chopping up old roots in the process, keeps the soil light and fresh.

If you've been fertilizing frequently with a synthetic fertilizer the salts can build up in old soil mixes over time, so it's good to periodically start fresh with new potting mix. If you use fertilizers regularly, starting with fresh potting soil every three years is a good idea.

Soil aside, ask yourself if anything else has changed. Is the location shadier, for example, because the trees/shrubs outside have gotten larger?  Was the weather cloudier so the water in the pots didn't dry up as quickly? Was someone else watering or fertilizing for a period of time? Have you had the same plants growing for a few years without starting fresh with new cuttings? (Plants can get tired just like people!)

If you can't figure out what happened, the best you can do is to take new cuttings and root them, dump out the old soil and clean the containers very well, and start fresh with new soil. The reality of plants and gardening is that sometimes we never figure out what has caused the symptoms we see!

I hope this helps,
C.L.