NEIL SPERRYGardener's Mailbag

Dear Neil: Will this weed die out once it gets hot? I’ve tried spraying it, but so far it hasn’t worked.

A: This looks like annual ryegrass that has been mowed repeatedly. In any event, it’s a cool-season grass that will, indeed, die out within the next few weeks. I’m not sure what you might have been using as your spray, but there is no herbicide that will work to kill grassy weeds in a lawn without harming the lawn. Your only way of dealing with this one will be to apply pre-emergent weedkiller granules between Aug. 25 and Sept. 5.

CONSIDER OTHER TREES

Dear Neil: My pear tree has a hollowed-out base and my weeping willow is dying. What type of person would be able to help me save them?

A: You would want a certified arborist. However, before you spend a lot of money on those two specific types of trees, you need to know that both have short life expectancies. If you have an ornamental pear such as Bradford, their productive life in landscapes averages less than 15 years before major limbs start to break and split out of the trees. Weeping willows can be expected to live 5 to 7 years in a landscape before cottonwood borers, cotton root rot and other fatal flaws take them down. It’s a shame in both cases, since they’re pretty trees, but as with all fast-growing species, they come with short lives. All of which is to say that you might be better advised to spend your money on high-quality replacement trees than on hiring someone to doctor these. Of course, I don’t have the benefit of seeing a photo of your trees. But I thought it prudent to warn you.

COMPOST

Dear Neil: Do you recommend organic compost as a treatment for our lawn? If so, how often?

A: I’m a big advocate of compost (all compost is organic) as a soil amendment as you work up flower and vegetable beds, also as you prepare for shrub and groundcover plantings. But I don’t feel that it’s necessary to topdress turfgrass with it. If you mulch your grass clippings and let them return to the surface of the soil each time that you mow, you’ll be adding them as a source of organic matter automatically all through the growing season. No more will be needed. Save the compost for use elsewhere in your gardens.

Have a question you’d like Neil to consider? Mail it to him in care of this newspaper or email him at mailbag@sperrygardens.com. Photos submitted with letters must not come from previously published material and may be used for publication. Neil regrets that he cannot reply to questions individually.