WASHINGTON — From late-blooming flowers to blankets of fallen leaves, there’s still time to care for your yard.
Fabulous is not your imagination
Are you under the impression that there’s a more spectacular dose of fall color than most years? You are correct, oh wise one.
Despite it seeming like it was a cold, wet summer, the region actually had almost exactly normal rainfall and temperatures. What didn’t happened were the searing heat waves of previous summers, which no plant — or person — ever enjoys.
Steady moisture in the soil and that lack of microwave days set the stage for a very good crop of healthy, happy leaves on local trees. Then the recent stretch of warm days and cool nights concentrated the sugars in those leaves, making their true colors exceptionally bold once their color-hiding chlorophyll went away. Maybe Nature is giving a close-to-perfect fall to make up for that Polar Vortex poleaxe of a winter.
Make good use of these great leaves
The more colorful the leaf, the more plant-growing energy it contains — which means that this year’s crop of fall color will make exceptionally good compost and mulch. All you have to do is shred them.
And yes, you do have to shred them. Whole leaves mat down like a tarp, smoothing lawns and other low-to-the-ground plants. That trait helps trees reduce plant competition in the wild. Whole leaves also take years — as opposed to months — to turn into rich, black compost.
Mow any leaves that fall onto your lawn into your lawn with a sharp blade. The pulverized leaves will provide a gentle feeding and help reduce or eliminate the build-up of thatch. Don’t bag the leaves or use them for compost if you mow them on a treated lawn. Any compost made with such leaves — even by a municipality — can kill plants.
Use a leaf blower set on reverse to pick up and shred the rest of your leaves in one easy motion. Then bag the shredded leaves for use as the perfect mulch next year You can fit 10 to 20 times as many leaves into a single bag after they’re shredded. Or use them as the brown bulk in a proper compost pile. Doing that means no clippings from a treated lawn or more than a little bit of kitchen waste.
There’s still time to feed your lawn, but make it legal
Bill in Alexandria writes: “Is it OK to fertilize a lawn in October or November before winter sets in? If so, what type of fertilizer would you suggest? Something like a 10/10/10 or a 20/10/10?”
Cool season lawns, such as fescue and bluegrass, should be fed in the fall, Bill. That’s ideally between mid-August and mid-September. The last date you can legally feed a lawn in Maryland or Virginia is Nov. 15, but the sooner the better. Lawns love September feedings.
And both of your fertilizer suggestions are stone cold illegal at any time. Homeowners are no longer allowed to apply any phosphorus (see below). Lawns don’t need it, and it’s the fertilizer component that’s held most responsible for injuring the fragile Chesapeake Bay.
The new laws require — and lawns thrive on — just a reasonable amount of nitrogen, which the No. 20 is not. So please get a fertilizer that’s labeled as legal for lawns in Maryland and Virginia, which, by the way, includes just about all natural and organic product. Hint, hint.
Virginia’s law mirrors the one in Maryland. It’s fully in effect as of July, but alas, no readable version exists online as of yet.
Science Saturday sidebar: What numbers like “20-10-10” mean
By Federal law, all fertilizers — chemical or organic — must prominently display three numbers on their labels, known as”NPK” numbers.
- N: This represents nitrogen — the primary plant food, especially for non-flowering plants like turf grass. A 20 would mean the fertilizer delivers 2 pounds of nitrogen per 1,000 square feet of turf. That is a little more than double the new legal limit of 0.9 pounds.
P: This represents the phosphorus content. Phosphorus induces flowering and is therefore close to useless on a lawn anyway.
K: This represents the potassium content. Potassium improves the overall health and vigor of most plants, but lawns don’t need it either.
Under the new laws, a perfect NPK for use on a lawn would be 9-0-0.
Water really is the best way to deal with aphids
Chris in Brinklow — which is just a little east of Olney — writes: “Do you have any suggestions for a non-toxic control for the aphids that have invaded my weeping willow? It was mulched with wood chips — which I know you don’t advise, so I recently replaced them with compost. There is also an ant colony feeding on their nectar. One website suggested spraying them off with a garden hose. This would be tough since there are hundreds of them on each branch.”
And yet, that’s the exact right cure, Chris — at least if the water is delivered in a sharp stream. University studies have found high-pressure sprays of water to be more effective than chemical pesticides against aphids – – so blast away.
And if the aphids return next season (which is doubtful, now that you’ve disposed of the plant-weakening wood mulch), use boric acid traps to get rid of the ants. Those ants are actually “raising” the aphids so they can “milk” them for their sweet honeydew.
Spare that hydrangea
Patricia in Reston writes: “My hydrangea did not bloom this spring like it usually does due to a cold snap. It’s been growing nicely all summer and is now blooming. Should I remove the blossoms?”
No, Patricia, you should not imitate our local sports teams and seize defeat from the jaws of victory.
Most of the region’s hydrangeas were severely set back by the horrible winter, and can be expected to act a little unpredictably — which yours has done in a good way. Enjoy the flowers and let them dry naturally on the plant — then you can pull them off if you don’t like the look.
But when it comes to just the faded flowers, don’t prune your — or any — hydrangea. Most bloom on old wood, and fall pruning can expose any plant to severe winter injury. If you must prune, do so right after the new flowers form in late spring.