Q: What is the best mulch to use around mature oak trees? Willie Benton, Butts County
A: The absolute best mulch is hardwood chips from an arborist’s truck. The second-best mulch is pine chips with needles, and the third-best mulch for an oak tree is mixed wood chips and leaves. Pine bark chips and pine straw are easy to purchase and spread, but ultimately, they are not the best mulch for trees. They break down so slowly that the trees get no nutrients. Overall, it’s better for trees to receive fertilizer slowly throughout the year. Although you might not think of arborist chips as fertilizer, that’s what they are. Fungi and bacteria colonize the chips and release nutrients the tree needs. Mushrooms sprout, showing the healthy microsphere below. This, plus the normal functions of preventing weeds and holding moisture in the soil, makes hardwood chips the champ for tree mulch. You can sign up to receive free chips from local arborists at chipdrop.com.
Q: I was given a ficus tree as a wedding gift 32 years ago. I keep it inside during the winter, but the rest of the year, it lives outdoors. Three years ago, leaves started curling up, which I learned was caused by ficus thrips. I’ve considered heavily pruning it back and getting rid of the infested leaves. Linda Brown, email
A: We have to take special care of this heirloom! Living outdoors is good because natural predators love to eat thrips. When you take the plant inside for the winter, spray the whole plant with horticultural oil or neem oil, making sure every surface is covered. Frankly, oil spray will kill only about half of the thrips population, leaving the other half of the crowd happily sucking sap from the leaves. If you want better control, use an insecticide that contains imidacloprid, such as Bonide Systemic Houseplant Insect Control. This will likely kill some of your beneficial insects, but your ficus will be protected for a year. Next spring, don’t use the insecticide, so your beneficial buddies will enjoy fresh thrips for the outdoor season.
Q: How do I keep monkey grass from emerging in several different places in my yard? Kevin Casto, Marietta
A: My recommendation will be tedious, and you will hate me before long, but the only way I see to get rid of individual patches is to treat each one individually. Get a foam paintbrush and some nonselective herbicide. I recommend glyphosate or herbicidal soap. Dab the herbicide on each clump. Glyphosate is systemic and will travel down the leaves to the roots. Herbicidal soap kills only the leaves. The foliage will turn yellow by fall, and most of the clumps will be dead by next spring.
Email Walter at firstname.lastname@example.org. Listen to his occasional garden comments on “Green and Growing with Ashley Frasca” Saturday mornings on 95.5 WSB. Visit his website, www.walterreeves.com, or join his Facebook page at bit.ly/georgiagardener for his latest tips.
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