Meet Mike in Leesburg
Mike will appear at 11 a.m. and 1:30 p.m. on Sunday, April 19, at the Leesburg Flower & Garden Festival.
Corn gluten timing: Look for the yellow flowers
“Meta” left a comment last week on WTOP.com asking whether my old “forsythia hint” is still valid for timing the application of corn gluten meal on lawns in the spring. He says there’s some forsythia growing in his neighborhood, “but no sign of blooms yet. There’s also a redbud tree just down the block that may be easier for me to monitor,” he adds, asking whether that timing advice is still good as well.
“If not, I may just give in and buy a soil thermometer this year.”
Well, Meta — having a soil thermometer would land you smack in the middle of the popular crowd, that’s for sure. But yes, the appearance of the first blooms on redbud and forsythia is a great visual signal that the time has come to apply corn gluten meal as a natural springtime weed-and-feed to prevent the dormant seeds of summer annuals such as crabgrass from successfully sprouting.
The time has come for all good men and women to come to the attack of their crabgrass
The winter weather that tried to kill us was certainly successful at killing annual weeds such as crabgrass for this season. To quote the good Dr. McCoy: “Those plants are dead, Jim.”
That’s right — crabgrass plants are not perennial; they die every winter.
But their seeds survive — and that’s why we suggest every spring that you apply corn gluten meal to your lawn when the soil temperature reaches 55 degrees (as measured 4 inches down) to prevent at least some of those dormant seeds from successfully sprouting.
The soil temp at 4 inches down in Prince George’s County was 47 degrees on Friday. But that doesn’t mean you should chill out, as it can rise fast this time of year. And it’s always better to get any pre-emergent down a little early than too late.
So you have permission to launch your gluten, cats and kittens!
One climactic issue: Corn gluten works best at weed prevention when the material gets wet and then stays dry for a while, which may be difficult next week, as rain is predicted pretty much from Tuesday on. So do your best with timing — either get it down Saturday or be ready when the next round of rain ends.
But be assured that corn gluten is still an excellent food for your lawn, no matter the weather. And good food, plus a never-lower-than-3-inch cut with a super-sharp blade, is your best protection against weed woes.
Plants don’t like to be power-washed
John in Stafford writes: “Our building was power-washed last summer, which made the outside look brand new, but unfortunately, killed some of the landscape plants — like rhododendrons — growing close to the building. It also hurt a couple of mature holly trees, which lost most or all of their leaves. But they appear to still be alive. Will new leaves develop, or is this a lost cause?”
Well John, only time will tell whether the plants can leaf out again. You should know in about a month. If they do produce new leaves, mulch them with an inch or two of peat moss covered with an inch or two of compost. No wood mulch — that would only stress them further.
If they come back but sections don’t look so hot, prune away the bad-looking parts. Hollies can be cut back pretty severely — almost to the ground — and generally regrow, although they won’t look like much for the next few years.
If that’s the case and you don’t want to look at slowly recovering plants, replace them — but follow the same mulching advice: peat moss covered with compost. No wood!
Clay soil = terrible tomatoes
Abby in Burtonsville writes: “Last year, nearly all my tomatoes had sores on them that looked like they were caused by anthracnose (based on Internet pictures of that fungal disease). Can you recommend how to combat it? I grow in both raised beds and directly in the ground. Our soil is mostly clay, and we’ve only had the garden for two years, so we are still working at improving the soil.”
Anthracnose is a nasty disease — and the appearance of “sores” on the fruits is a perfect description of its effect on tomatoes. So I accept your diagnosis, Abby.
Go out right away and trash any old mulch and plant debris from the area. The spores survive winter, and you want them to be gone long before this season’s plants go in.
Then, dig out and dispose of some of that clay. Just throw it into the woods. Anthracnose only strikes plants in poorly draining soil, and nothing drains worse than clay. Replace the clay with compost and screened topsoil with a big bag of perlite mixed in to help even more with the drainage. And I strongly suggest you abandon your Flat Earth gardening and go completely to raised beds. You’ll do a little work up front and reap years of reward.
No matter what, be sure to mulch this year’s plants with two inches of compost on the surface of the soil. Don’t till it in: The living organisms in compost can directly combat nasty spores that blow into your yard. A compost mulch can prevent many diseases from ever taking hold.
Time for the cool-season crops — not tomatoes
Yikes! We’re already getting tomato-growing questions?!
Time for me to remind everyone that the crops of summer — tomatoes, peppers, eggplant, cucumbers, squash and such — should not be planted until nighttime temperatures are reliably in the 50s, which won’t happen until May. Generally around the first or second week of May for D.C. and the second or third week for the outskirts. Daytime temps don’t matter, just the nighttime lows.
Don’t push it! Warm-weather plants that get cold at night early in the season perform poorly all season long.
But now is the time to grow cool-weather munchies, such as lettuce, spinach, peas, broccoli and such. The soil is still way too cold (it isn’t even 50 degrees down there yet!) to sprout any kind of seed, so buy starter plants for at least your first run of greens and broccoli. The plants don’t mind weather that’s too cold to sprout seeds.
Peas need to go in soon to be able to produce their tasty eating before summer heat crushes them and you can’t generally buy them as plants. So pre-sprout your pea seeds indoors in moist paper towels and then plant the sprouted seeds outside. Again the plants will do fine despite the cold soil, as long as the seeds have sprouted.
Remember: Almost all seed requires a warm soil to germinate — that’s why spreading grass seed in the spring is just food for birds and vermin.
