Reseeding Lawns, Mulch Fungus and Tomatoes

JR in Columbia writes: "What month or season is the best time to use a plug aerator on a lawn and to lay down grass seed?"

Well, JR, the ideal window of time for reseeding, overseeding and just plain seeding is rapidly closing. You get the best results when you sow that seed between August 15 and the end of September. You can probably still get good results, but you'll have to act fast—before the soil cools down too much for fast germination. So get the seed down NOW.

Then be ready to handle any leaves that fall on the lawn very gently, so's you doesn't disturb the young grass. Have a yard vac ready to gently remove any leaves when they fall. (Most leaf blowers have a reverse setting that can do this.) Whatever you do, don't rake the new grass or let any leaves lay on the lawn. They must be removed, and gently.

Aeration is easier; now is still an excellent time to remove those plugs of soil and sod and give your grass some much-needed breathing room at the root zone. Our favorite turf grass expert, Iowa state University's Dr. Nick Christians, tells us that your lawn just need a month afterwards to recover before the ground freezes hard for the winter.

But be aware that you should NOT seed or aerate in the Spring, so get moving!

Throwing in the Turf Towel

Michael in Potomac is ready to give up on his grass. He writes: "I live in a very shady townhouse development with a postage stamp size front yard that currently grows a poor excuse for a lawn. I'd like to remove all remnants of the grass and plant a shade loving ground cover that will need little maintenance except for occasional weeding. What do you recommend I plant? And when is the best time to prepare the soil and plant?"

You should wait until Spring, Mike. Then till up what's there, remove all the old grass, level it out, and then water the bare soil. Don't plant anything yet. Wait a week to ten days and all the dormant weed seeds your tilling has uncovered will sprout. Then carefully hoe them off at the soil line with a new, sharp-headed hoe, or a hoe whose head you have sharpened. Don't disturb the soil; just slice the young plants off right at the surface. This creates a ‘stale seed bed' and eliminates 90% of your potential future weed woes.

Then spread an inch or two of compost on top, level that out and plant vinca or pachysandra. Buy more plants than you think you'll need. The tighter you position the new plants, the quicker the area will fill in, thus keeping your future weeding chores to an absolute minimum.

Tomatoes: Their time is up!

Just got a great question from my WTOP colleague Colleen. She writes: "My husband wants to know when it's time to give up on the tomatoes in the garden and just pick them green."

Excellent topic for this time of year, Colleen! I generally start pulling off any new flowers that form on my tomato, pepper, cucumber and other summertime plants around September 15th or so—this directs all the plant's energy into ripening up existing fruits. Then I'll strip the plants when the nights are reliably dipping down into the 40s.

I used to cover my plants at night to try and keep them producing longer, but its messy work and I don't think I ever got one extra tomato for all my late-night troubles. Better to pull up the plants, put some garlic cloves or salad greens in their place and bring the green tomatoes inside to finish ripening up on the kitchen counter. NOT in a sunny window or in any other form of direct sunlight, by the way. That actually harms the flavor.

Wood Mulch stained our lives!

Julie, who hosts a super-fun website about tacky treasures (www.tackytreasures.com; I can't decide if my favorite is the Pope bottle opener or ‘Jesus Playing Football'), writes: "I'm a regular Garden Plot listener and wonder if you've heard of this problem. My husband and I discovered tiny dark spots on our cars and the picture window of our house. Internet research leads us to think its artillery fungus that came from our mulch. What's the best way to remove it from our cars and windows? How do we get it out of our mulch? And how can we be sure that any new mulch we purchase doesn't have this fungus?"

I've been warning about this problem for a decade now, Julie. Shredded wood and bark mulches are very prone to hosting this destructive fungus, which shoots tar-like spores as far as 30 feet. All wood mulches can cause the problem: ‘triple premium shredded bark', wood chips, those God-awful chipped up pallets spray painted a garish color...anything wood.

Use black yard-waste compost (like Maryland's great LeafGro product) as a mulch instead; it prevents weeds just as well as wood, looks just as nice, feeds your plants and causes no fungal problems.

Now: A professional window cleaner should be able to get the spores off your glass, but unfortunately, all the research I've seen says that the stained areas on the cars will probably have to be sanded down and repainted. These spores are living things, and they actually worm their way deep into the finish. Same when they appear on vinyl siding; they're virtually impossible to remove without making the surface look awful.

And most homeowner's insurance started excluding such damage a decade or so ago when the claims became too numerous. Expensive mulch, eh?

Chop up your hostas!

Christopher in Woodbridge writes: "I have some four-year old hosta plants that are getting quite large. Is it safe to separate these plants into smaller ones and replant them elsewhere? If so, when would you recommend? You've warned us not to plant bulbs until after Halloween: does the same thing go for pulling up, separating and replanting existing plants?"

Not at all—in fact, this is a GREAT time of year to divide overgrown herbaceous perennials like hostas, Chris. Especially hostas, in fact, as they're darn near invulnerable. Dig up the big clumps and then use a sharp shovel to slice them apart into halves or quarters, and then replant the sections.

You can also do this safely when the new growth appears in the Spring. Just don't feed them; then or ever. Hostas need no further encouragement and actually grow better without it.

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