Garden Plot: Tips for lawn seeding and tree planting

Meet Mike in Warrenton, Virginia at 1 p.m. Saturday, Sept. 5

Fall is the best time for gardening. The soil is still toasty warm, but the weather is nice and cool, and many things only grow well in the fall. Mike will reveal all the great things you can get growing now when he delivers a free talk,”The Second Season: Garlic, Pansies, Salad Greens and More,” the Lee Highway Nursery, 7159 Burke Lane, Warrenton, Virginia.

Prime time to kill grubs with milky spore

Lisa in Sterling writes: “With the late summer weather turning cooler, when do you advise putting down Milky Spore and planting a couple of trees?”

Well Lisa, the weather was coolish and wonderful when you emailed us Thursday, but now we’re back in the sauna again — and the long-range forecast is for more of the same heat and humidity. So hold off on any tree planting until this latest heatwave breaks. You’ll avoid heat stress on top of the transplant shock that always accompanies such plantings.

However, do apply Milky Spore now to control grubs in your lawn and garden beds. A totally natural and safe grub killer, Milky Spore works best when the soil is warm, which is now, and when the nasty grubs have grown to a large size and are actively chewing on the roots of your lawn and other plants, which is also now.

It’s almost time to plant new trees

Well, the cool and crisp weather we recently enjoyed turned out to be another cheap tease from Mother Nature, as we are now firmly back in the torrid tropics. To better insure long-term success, wait to plant new trees and shrubs until the weather for the week following your planting is predicted to be in the 70s to low 80s. No 90s! Torrid temps really stress new plantings.

That said, September is otherwise the perfect time to plant a tree. Because they won’t have to endure searing heat for months afterward, the survival rate for fall-planted trees is much higher than for trees planted in the spring.

And, you can generally get a really good deal at this time of year as garden centers want to clear out their remaining stock.

Everything you know about tree planting is wrong

Now, you’d think that something as basic as planting a tree would be easy, and that most people—especially landscaping professionals—would do it correctly. Wrong-O! Some really bad ideas have become commonplace, even generally accepted wisdom, despite the fact that they all shorten the life of the poor tree. Here’s how to do it correctly:

  • Wait until any heatwaves break and the soil is nice and dry. Never plant in wet soil!
  • Dig a wide hole, but not a deep one. You want the root flare of the tree to be visible above ground.
  • If the tree is balled and burlaped, remove all the wrappings. If left intact, that cage and bag will constrict the roots of the tree and prevent them from growing out laterally. Being planted “in the bag” is a huge cause of tree failure, tree-toppling and even early death.
  • If the tree is potted, turn the pot on its side and gently work it around until you can slide the pot off. Then, work some of the soil away until you can see the roots. If you’re feeling brave, spread those roots out a little bit. Same as above, you want to encourage those roots to spread outward. That pot was ‘training’ the roots to go around in a circle.
  • Place the tree in the hole and check the depth. If the root flare will be under the soil line, take the tree out and add some soil to the hole to raise it up. It should NOT look like a lollipop stuck in the ground when you’re done!
  • Fill the hole with the same soil you removed. This is very important: Do not “improve” the soil in the planting hole with compost, peat moss or anything else, otherwise the roots will just circle around in that nice little island of good soil. If you fill the hole back up with the same soil you removed, the roots will not be so inclined, and will leave home in search of a job.
  • Then, let a hose just drip gently—like, leaky faucet-gently—at the base of the tree for several hours. Repeat this watering twice a week until we get some good rain.
  • Do not use any kind of wood or bark mulch near your newly-planted tree.
  • If you want to do something nice, mulch-wise, for your tree, spread a 1- to 2-inch deep layer of compost around it, beginning 6 inches away from the trunk and going out as far as you like. Wood mulch kills trees; compost protects them.
  • No matter what, do not let any kind of mulch pile up against the trunk of the tree or else the bark will rot and the tree will die. And yes, that means all the volcano-mulched trees you see are dying.

Lawn care timing: seed now, gluten later

Mark in Fairfax writes: “I recently had some landscape work done that required the removal of a good amount of my front lawn. Now that the work is complete, I want to time my seeding and corn gluten meal application. When is the soonest I would be able to start? Should I seed first or apply corn gluten first?”

You should start as soon as possible, Mark. September is the perfect time to sow cool-season grass seed. But forget the corn gluten meal until spring. This natural pre-emergent prevents all seeds from germinating, including grass seed. (Yes, you could spread it a month after all the new grass was all up, but that’s getting pretty late in the season, and it’s just not necessary.)

Instead, have a nice load of compost delivered, level it out, then sow the seed. Rake the seed into the compost and gently mist the area every morning for a few days. The seed should sprout quickly, and the compost will provide all the food your lawn needs until spring.

Hey kids: What time is it? It’s garlic planting time!

Get some hardneck garlic from a seed catalog, garden center or local farmer’s market. Don’t use supermarket garlic. It’s the wrong type (softneck) for growing in our region and was probably treated with sprouting inhibitors.

Gently separate out the individual cloves from the bulb and plant each clove butt down, pointy end up, about 6 inches deep and 6 inches to 8 inches apart in your loosest, richest, best-draining soil. Raised beds are ideal for garlic growing.

The cloves will develop nice roots, go dormant over the winter and grow like mad in the spring. Then you’ll harvest a nice big head full of cloves from every single clove you planted—a much better return than the market, especially these days!

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