Question & Answer – February 2008

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Question:  Is there anything I can do now to prevent weeds in my vegetable garden at our weekend house near Lake Texoma?  They are mostly grasses.  M.R., Fairview.

Answer:  Keep the soil loose by adding generous amounts of organic matter as you till it and make it ready for spring plantings.  Those plantings need to begin immediately with crops like onions and snap peas.  Loose soil makes cultivating weeds easier.  Unfortunately, there is nothing you can do now in terms of fumigants or pre-emergent herbicides.  You can spot-treat with a glyphosate weedkiller to eliminate grasses in your garden, but there is no label clearance given to do that during the time that the vegetables are actively growing, so we cannot recommend it to you. However, once the crops have finished producing, you can spray the weed leaves and runners and expect complete control.  You may have to wait until July to do this, but it will be worth the wait.

Question:  I cut back Silverado sage plants last spring. They were 6 feet tall and now they’re 2 feet tall.  Would they survive transplanting now?  No name, no city.

Answer:  A lot of it would depend on what vigor they have left after such a heavy trim.  If they rebounded and grew well last summer, they’re definitely worth moving.  This is the time for both transplanting and pruning Texas sage plants.  Good luck.

Question:  My potted bougainvillea was in full bloom when I brought it in for the winter. It is in the process of dropping all its remaining flowers and leaves.  When should I prune it before I move it outside for the spring, and by how much?  T.S., Crawford.

Answer:  Ideally, you would only have to prune it gently to restore its good shape. However, if it was set back badly by its time indoors you may have to remove as much as half of its top growth.  Do that about the time you take it outside in late March or April.  Pruning stimulates new growth, and you want that new growth to be hardened to outdoor conditions from the outset.

Question:  Is it safe to use Roundup to kill weeds in my dormant bermudagrass lawn now during the winter?  D.T., Flower Mound.

Answer: I have never felt comfortable recommending that practice, especially when I’m writing or broadcasting to a statewide audience (South Texas lawns often don’t go completely dormant).  The problem is that if there are green runners down within the bermudagrass turf, you run a significant risk of killing patches of the lawn.  Use a broadleafed weedkiller containing 2,4-D to eliminate the non-grassy weeds during February, and just ignore the grassy weeds. They will disappear into the turf as the bermuda greens back up again in a few weeks. 

Question:  I planted a new lilac bush last fall. I have taken good care of it over the winter.  When should I prune it, and what do I need to do to ensure it will do well?  J.K., Azle.

Answer:  I will answer your specific question first.  Spring-flowering shrubs and vines should always be trimmed immediately after they bloom.  Flower buds form over the winter and you don’t want to cut those off.  New plants need to be hand-watered for their first year in our landscapes.  Sprinkler irrigation alone is simply inadequate.  Now, to offer an editorial opinion which you may choose to ignore:  lilacs really struggle in Texas. We are simply too hot and too dry for them to prosper.  Veteran Texas gardeners may argue, but I’m a veteran, too, so I have permission to rebut.  They claim that they have lilacs that have been in their families for decades. And, they probably do.  But it becomes a quality thing.  Those plants may be 3 to 5 feet tall and wide, and their flower heads may be the size of golf balls. The same plants in the North would be 15 feet tall and wide, and the flower heads would be the size of footballs. They’re just too much struggle for the limited reward.  It’s just one guy’s opinion. No need for others to write.

Question:  Could too much water cause oakleaf hydrangeas to look bad?  I have seven plants against the east side of my house.  All but two in the middle are doing well. They stay the wettest.  What causes them problems?  K.J., Mansfield.

Answer:  While they benefit from moist soils, they may be getting too much of a good thing.  Much of your city also has heavy clay soil, and that can add to the issue.  If it’s alkaline, black clay, then cotton root rot also is a possibility.  That’s a soil-borne fungal disease that does bother them occasionally.  There is little you can do other than to add a soil acidifier (sulfur product) to lower the pH as best you can.  However, that’s a reach.  That may or may not be your problem.

Question:  I am planting a 500 sq. ft. garden this spring.  I would like to grow large-leafed hostas, plus ferns. What are some good choices?  I plan on purchasing landscaping mix, fine pine bark and putting the two together 6 inches deep.  What groundcover would work? Any suggestions?  K.D., Richardson.

Answer:  Stay away from the large-leafed hosta varieties. They really struggle with the Texas climate. Go, instead, with small types. There are scores of them available. Buy from local nurseries to get the freshest possible plants. They should be widely available in March and April.  If you like that bold look, consider cast iron plant (aspidistra), too. It’s an evergreen plant, so it keeps putting out its drama 12 months a year.  It is a Zone 8 plant, meaning it will be fine in most winters in Richardson. Be ready, however, to cover it when  temperatures fall below 15 degrees.  I have combined these plants with wood ferns primarily, but there are several types even within that group, plus you could use holly ferns, autumn ferns and others.  I have used Beacon Silver lamium as a colorful groundcover in this sort of setting.  It grows luxuriantly and must be kept within bounds, but it’s a lovely sprawling plant.  The various types of elephant ears work great, too.

Question:  How would Encore azaleas do for me in Longview?  They would be at the back of a bed across the front of our house. It’s almost total shade.  I don’t want to make that big an investment if it wouldn’t work.  C.D., Longview.

Answer:  Encore azaleas would do absolutely famously in Longview, but they need more sun than that.  Find a place somewhere in your landscape and include some, but stick with hollies or other shade-proof plants in that dark setting.

Question:  It’s rose-planting time. You had a list of the most trouble-free roses a few months ago. Could you repeat it?  A.H., Wichita Falls.

Answer:  We’ll take you directly to the TAMU web page for EarthKind roses. Click here to see it.

Posted by Neil Sperry
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