Q: Our forsythia bushes have not bloomed for the last several years. They are supposed to start blooming soon, and if they don’t, my husband wants to remove them. We restrict our pruning to the time shortly after they should have bloomed, so we are not cutting off the flower buds. They are growing in full sun. What can we do to force them to bloom?
A: There are a few possible causes for spring-blooming shrubs failing to bloom. As you already know, pruning in the fall or winter cuts off flower buds. Forsythias, lilacs and most other species of these shrubs prefer growing in full sun. The more shade they get, the less they flower.
If the shrubs are unhealthy for some reason, such as waterlogged soil or recurring diseases, they may not bloom. Forsythia flower buds are less hardy than the leaf buds and can be killed by winter or early spring freezes. If they only bloom near the ground where buds are often protected by snow, then the buds that don’t bloom were killed during a winter cold spell. You should get rid of them and plant a newer, hardier variety.
If they bloomed well in the past and have stopped, it may be because old stems do not bloom as well as younger ones. Most spring-blooming shrubs flower best on stems two to four years old. That is one reason we remove one-fourth of the stems at ground level each spring after they bloom. This forces the plant to grow new stems each spring, and after four years, we have a new plant of only blooming young stems.
If you have an old plant with only a few large stems, it may take a few more years to obtain the effect you want — cutting down one large stem may remove a large section of the plant. If you do not depend on the plant to screen a view, you can just cut down the whole thing. This will force the plant to grow all new stems this year. This involves more risk because some plants do not send out any new growth; they just die.
Forsythias do not have many other redeeming virtues, so that may give you the opportunity to plant a better plant. Newer varieties of forsythias contain more cold-tolerant flower buds.
A last-chance option would be to fertilize the shrubs this summer with a fertilizer that promotes blooming to see if they bloom better next year. Three numbers are always on the fertilizer package. The middle one is for phosphorus. If it is about twice as high as the first number (nitrogen), it will work. It does not matter what kind you get, but be sure to follow the label directions.
Q: Our yard is properly graded, but it is downhill from some other homes. Water takes its time to go through our drainage swale, and the puddle is killing the grass and flowers. We would like to speed it up. Can we trench it? And how should I do trenching?
A: The first question you must answer when looking into trenching is, where is the water going to go? Is your yard the lowest one, or does the water go to another yard? At some point, the water in a subdivision either ends in a retention or detention area or goes into a stream or river. Sometimes it goes into the storm sewer, but that will still go to the river.
Water traveling over land is often supposed to get to the lakes and streams more slowly than the water in the pipes. This allows the landscape architect and engineer to design the property to not flood downstream or downhill. If the water is supposed to travel on the surface in your yard, trenching may cause a problem for a neighbor.
A trench is easy to dig with a machine and harder if you do it by hand. In many yards, the drainage swale is also where all of the cables are buried in your yard.
Once the trench is dug, it can be filled with a pipe or with gravel. Either one should be wrapped in landscape fabric to prevent dirt from filling the gaps where water is supposed to flow. Tree and shrub roots can find the trench and eventually fill the drain so that it does not work well. The landscape fabric helps prevent roots from getting in. The trench should flow downhill at least 1 inch per 10 feet.
Now we must consider my first question: Where is the water going? The trench and pipe cannot just end below ground because the water must come out. Once a plugged pipe is filled, it is no better than no pipe at all — the water has to go somewhere. If the ground slopes sharply away from the low end of the pipe, it can come out of the ground and let the water out.
Planting plants that like lots of moisture may be a better solution. There are many wetland plants that will tolerate occasional drying out and will grow well in this kind of location. I have written about these plants in the past, so let me know if you want a list.
E-mail questions to Jeff Rugg, University of Illinois Extension at firstname.lastname@example.org. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.
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