SPURGE GROWS in a bermuda lawn.

Dear Neil: How can I get rid of spurge in my lawn? I believe I’m calling it by the correct name. It is very short and has the milky white sap. I keep digging it out, but it just keeps coming back.

A: Spurge is a lowgrowing, broadleafed, hotweather annual weed that is fairly easily controlled with a broadleafed weedkiller spray containing 2,4-D. There really is no need to dig it out. Use a pump sprayer and spot-treat the individual plants. They’re round and clump forming, so they’re easily sprayed. In the meantime, ramp up the water and fertilizer you give your lawn so it can crowd out the spurge. It only shows up in parts of lawns that need a little more care and attention.

PROTECTING OAK ROOTS

Dear Neil: We have huge live oaks on our South Texas property. They’re more than 24 inches in diameter, and recently three have died due to trenching for pipelines. How far away from the trunks should the trencher be kept?

A: That’s not an easy question to answer because root systems aren’t always symmetrical. In general terms, if trenches are beyond the drip line (outer reaches of the leaf canopy), you should be fine. However, that’s not always practical. Hopefully the trenches can be laid out in a path that keeps them 25 or more feet from the trunks, and hopefully they won’t crisscross beneath the trees where they would cut roots on more than one side. That kind of cutting is best done in October or November, after the hot, dry summer weather has passed. However, people putting in pipelines don’t always have the flexibility or patience to follow those guidelines.

NON-BLOOMING ROSE

Dear Neil: I have a rose that is very healthy. I’ve had it for 25 years, but for only the past two years I have pruned it back a good bit in February. For those two years it has not bloomed at all. Why would that have happened?

A: It’s very possible that you have a spring-only bloomer. Many of the “old” roses only bloomed in the spring on growth they made the prior year. Many of our other spring-flowering shrubs and vines operate that same way, including forsythias, bridal wreaths, wisterias and Carolina jessamines. If you prune those heavily in late fall or winter they will not produce many, if any, spring blooms. The time to prune them, therefore, is immediately after the time they bloom (or should have bloomed). The only other cause I can think of would be if some environmental factor might have changed. If shade trees grew larger and suddenly cast too much shade onto the roses, that would prevent good blooms, for example. And I’m assuming rose rosette virus is not a factor.

SPLITTING SATSUMAS

Dear Neil: Why are my Satsumas splitting open before they are ripe? What can I do to stop it?

A: This happens when citrus fruit is exposed to dramatic changes in environmental conditions, for example, temperatures, moisture and wind. If it suddenly turns hot, dry and windy, you might expect to see fruit splitting badly. Water deeply if temperatures are expected to run up quickly, especially if hot winds will accompany the warming trend. Your biggest goal will be to minimize the environmental stresses on the plants.

PLANT BLUEBONNETS NOW

Dear Neil: When do I need to plant bluebonnet seeds?

A: Now. Buy acid-scarified seeds. That’s a process where the seeds are treated with a strong acid under carefully controlled conditions for a short period of time to soften their very hard seed coats. You then plant them into lightly tilled soils away from lawngrasses and where you won’t be adding very much fertilizer. Keep the soil moist until they sprout and start growing well, then water as needed through the fall.

GRAPEVINE ERADICATION

Dear Neil: I have a grape vine that is taking over my fence. I’ve tried chopping it down and applying a weedkiller, but it keeps coming back. What can I do?

A: If it has any size to it, cut it off just above the soil line. Macerate the stump with a saw or ax and pour a broadleafed weedkiller (containing 2,4-D) onto the stump at full strength. Let it soak into the wood, but try to keep it from running off onto the ground. Repeat the next day or two until you have gotten a fair amount of the herbicide to soak into the wood of the root system. It will be carried throughout the roots where it should prevent any further regrowth.

Have a question you’d like Neil to consider? Mail it to him in care of this newspaper or e-mail him at mailbag@sperrygardens.com. Neil regrets that he cannot reply to questions individually.