Plant Problems: When to Pull the Plug

It’s so hard to say goodbye

Sometimes as gardeners, when plant problems arise, we need a little push to finally admit that a plant isn’t going to make it. I have to admit, it’s tempting to keep on spraying, fertilizing, pruning, watering and otherwise “nurturing” that plant that’s had only two green leaves for the last six months. For me it’s the challenge of bringing the plant back from the brink…I’ve done it before, why not this time?

Debbie finally had to make the call on the last of the tomato plants. Her babies, that she started from cuttings, developed blight and then caterpillars started munching on them and they weren’t really producing anything, and she knew it was time. We all have our reasons for holding on a bit too long, but this is my case for tearing that band-aid off quickly.

While holding onto a weak plant seems like a noble thing to do, and it can be warranted under some circumstances, there are plenty of times that the plant should be disposed of without delay. Plants under stress can become incubators for insects and disease.  It helps to diagnose the initial stressor (wrong sun exposure, poor drainage, drought stress, poorly rooted plant to begin with, etc.) to help in deciding whether to keep or remove the affected plant, and to prevent the problem occurring in other plants. The old saying that “one bad apple will spoil the bunch” pertains to plants in groupings as well.  Better to remove the one weak boxwood rather than allow it to become infected with blight which will wipe out the whole hedge.

Should it stay or should it go

When determining whether to treat or remove a weakened plant, consider these questions:

1. What could have been the initial cause of the plant problems? Often a bug or disease infestation comes after the initial stress. Poor air circulation, too little or too much water or sunlight, poor drainage, and physical damage are all common stress factors.
2. What are the current symptoms and what percentage of the plant is effected? It may have dropped a bunch of leaves, but were the leaves green or brown when they dropped? Are the leaves turning brown and not dropping? Do the leaves have brown spots or patches, or are they turning yellow? Always check for insects along stems and on the undersides of leaves. If you are not sure what these symptoms mean, talk to a volunteer master gardener or a certified professional at your local garden center
3. How mature is the plant, and how long has it been in it’s current location? If the plant came with a warranty from the nursery, this may make the decision for you.  A plant that’s been in place less than a year or two has not really had time to get established, and will have a harder time bouncing back from problems than a mature plant.
4. Could the plant problems spread to others nearby?  Group plantings of the same species, or plants in close proximity with similar cultural requirements may suffer due to the same stressor(s).

If you believe that keeping the plant threatens your landscape, you’d be better off replacing it. From a value standpoint, consider the cost (monetary and otherwise) of treatment versus the cost of replacing the plant. If you have suddenly realized it’s time to send one of your marginal plants on it’s way, congratulations! Now you get plant something new! To help prevent these plant problems, always resist the temptation to purchase discounted plants unless you are certain that they are only “shop worn” and not infested or diseased.  Happy gardening!