Shrubs - Forsythia
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  (March) I have two large forsythias. When do I trim them? I have also heard you should trim from the inside out. Is this correct?

  Trim your forsythia immediately following flowering. Since it produces multiple canes instead of one main trunk, do thinning cuts down close to the ground. Removing one third of the older, larger canes every year, should still leave you a good sized bush, but also allow you to have multiple young canes coming from the soil line. Forsythia blooms on one year old wood, so encouraging plenty of one year old growth, should give you ample blooms each spring.

  (March) Can I cut back the forsythia after it blooms? And isn't it time to cut back the Rose of Sharon bushes, crepe myrtles and butterfly bushes?

  Forsythia should be pruned after bloom. Remove one third of the old canes down at the soil line to encourage new growth. There is still time to prune Rose-of-Sharon, crape myrtle and butterfly bush, as all of these plants bloom on the current season growth. Try to do it soon since new growth is beginning.

  (April) I was hoping that you might be able to help me with a problem that I have been having with a particular forsythia bush of mine. It won't bloom. What would make a forsythia bush not bloom? It is planted near a cluster of pine trees, and at one time I was thinking that might be the reason, but I am unsure. Any insight you might have would be greatly appreciated.

  Forsythia bushes need a minimum of six hours of sunlight a day in order to bloom. Another limitation to flowering can be a poor pruning job. Forsythia plants set flower buds on 1-year old wood. That means that the growth they produce from the time they finish blooming until early fall is where the flower buds will be set. If your plants are shaped into perfect boxes or balls, or they are old woody plants, chances are they aren't putting on much new growth, and if you have flowers, they are sparse and only on the tips of these old branches. There are several schools of thought on pruning forsythia. I prefer to remove one third of the older canes each year down to the soil line. This leaves enough bulk to make a plant, but allows young canes to emerge from the ground each year. I like the graceful arching canes--sort of a living fountain. Some like to shear the whole plant back to the ground every two to three years. Either option encourages new growth and should be done as soon after bloom as possible. But do check the sunlight factor.

  (December) I have a hedge row of Forsythia which is beginning to die. The leaves are curling up and turning brown. I have been told it might be nematodes. If so how do I treat them and if not what do you think it might be and how can I correct the problem.

  At this time of year, I don't think you should do anything. Forsythia plants are deciduous and should have lost their leaves now. Granted, they should not have curled up before dropping, but lets hope for the best. Monitor them closely this spring and see how they bloom and leaf out. If you still have problems then, you would need to investigate further. You can do a nematode assay through your local extension office in the spring.

  We have several forsythia bushes in our yard. They are rather disheveled looking, and we want to trim them back. When is the best time to cut them back, and how severely could they be cut back?

  Forsythias are beginning to bloom now. They should be pruned immediately following flowering. The best way to prune forsythia, is to remove one third to one half of the older canes at the ground line. This greatly reduces the size of the plant, and allows young sprouts at the base. Remember, forsythia sets its flower buds on one year old wood in late summer to early fall. If the only pruning you did was topping it back, you are leaving old wood, which produces only scattered blossoms on tiny offshoots. A general guideline is to prune a third of the old canes every spring after bloom. This should give you many more flowers every spring.

  Can you tell me what is wrong with my forsythia bush? It has dead limbs in it. Last fall, I pruned out the older stalks like I thought I was supposed to. It is six yeas old, and normally produces long flowering stalks. It bloomed beautifully this year, despite the dead stalks. But I would hate to lose it.

  Pruning in the fall is not the right time for a forsythia, but that shouldn’t have damaged the plant–it simply took off potential blooms. Forsythia blooms on one year old wood, and sets flower buds in the late summer to early fall for the following springs blooms. It is possible that opening the plant up in the fall allowed for some winter damage. If the bark on the branches that died was split, that could have occurred during the first cold snap in December. If you will think back, the plants didn’t have a chance to harden off, it went cold overnight. Tender wood was damaged in some cases. Forsythia are normally tough plants. See how the plant comes out this spring. Any pruning that is needed should be done immediately following bloom. This should allow for the large new canes to grow all season long.

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