GARDEN DOCTORS: Battling suckers around base of trees

Jacquie B. of Petaluma asks: What's the best way to get rid of those shoots sprouting up the base of some of my trees?

I cut them off, but they keep growing back.

Those "shoots" are called "suckers," and they are vigorous vertical stems that ruin a tree's appearance. Both types of suckers - water sprouts that sprout up from the branches and root sprouts that grow around the base of the trees - are problems.

Water sprouts create too much shade within the crown (the center canopy of the tree) and are slow to flower or produce fruit.

Root sprouts compete with, and eventually overtake, the tree's trunk. If a tree is grafted, the root sprouts will never have the desired form, leaves, fruits or flowers of the grafted variety because they are the actual root system of another tree of that genus.

The best way to remove suckers is to do it while they're young, preferably ? inch in diameter, and during the early part of the growing season.

Simply take a hold of them and give a sharp tuck sideways, ripping them away at their growing points.

If this doesn't work, or the suckers are too old to yank off and it's too difficult, then cut them as close as possible to their growing points. If a sucker is not removed all the way back to its growing point, then new suckers can grow from the base of the old one.

You could also try holding onto the end of the sucker and hitting it at the base with a hammer, so it gets ripped off close to the ground. This will leave the remaining piece with a tattered cut rather than a clean cut, and chances are it won't grow back.

Theresa C. of Healdsburg asks: What can I do with my spent tulip bed? They look beautiful when they're in bloom, and then after that, I'm looking at unsightly, browning foliage. I planted them last fall, so this is their first year blooming.

Plant lots of summer blooming, color annuals in between the browning foliage. With an assortment of heights, the annuals will cover up the old foliage. Don't cut the foliage off until it's pretty dried up. The bulbs need the nutrients from the foliage to feed them for the next year.

If you want to, you could roll up the foliage and tie it in a loose knot so it will be out of sight.

You also could carefully dig them up. Without harming the bulbs, you can dig them and move them to a holding bed in a shaded area until the leaves all die back. Then simply sort out the bulbs, keeping the larger sized ones, and store them in mesh bags in a cool dark place with good air circulation. Replant them in the fall.

Alan N. of Santa Rosa asks: I have a large Magnolia x soulangeana (Tulip tree) that is doing quite well. Is it necessary to do any pruning on these trees?

Established Magnolias usually need very little pruning. Broken or criss-crossing branches should be cut out in midsummer when the tree is in full leaf. This will give the pruning cuts time to heal before winter, making them less susceptible to dieback.

Large cuts into old wood are best kept at a minimum. Magnolias can be slow to heal, and new growth may not begin until the second season after pruning. "Water sprouts" may develop after pruning, and those should be removed to maintain the shape of the tree.

Patti S. of Healdsburg asks: Every so often, a shoot from one of my rose bushes, grows in a very distorted way ... like someone flattened it out with a roller. The shoot is thick and very odd looking. It doesn't happen very often, but when it does, it's quite noticeable. Why does the plant do this, and is there a name for it?

Fasciation is one of the most unusual looking disorders gardeners commonly see on plants. This strange phenomenon affects a wide variety of plants.

The stems usually become enlarged and flattened, often developing a ribbed look. The flower stems can also be affected, although it's less common, with the flowers and buds developing on the distorted, flattened stems.

It is thought that fasciation results from unusual activity in the growing tip. This could be caused by insect, disease, frost or mechanical damage. It's also possible that viral or other infection could be the cause.

Although fasciation looks rather strange, it is harmless and will not affect the vigor or health of the plant. If you think it's unsightly, just prune the affected stems back to normal growth. There's no guarantee that other shoots won't also be affected.

Send your gardening questions to The Garden Doctors at pdgardendoctor@gmail.com. The Garden Doctors can answer questions only through their column, which appears twice a month in the newspaper and online at pressdemocrat.com.