Linda in Rockville writes: “I have had great success with my basil plants over the last five years. This year they initially grew well but quickly developed a black growth and withered away — both in a plot at a nearby garden for seniors and at our home down the street in planters.
Friends in surrounding neighborhoods have had the identical problem. Any insights from my favorite garden guru?”
Two insights, Linda.
One reason could be soil that’s been waterlogged by this summer’s excessive rain. It doesn’t matter how good your drainage is if the soil doesn’t ever get a chance to dry out. The other possibility is more nefarious — a basil blight that’s been sweeping the nation the last few years. And as with all true blights, there’s no cure, just heartbreak.
Basil wars: A new hope
Linda in Rockville said that her basil plants developed a black growth and withered away this summer. And the photos she included revealed that the problem affected the most common form of basil — the large-leaf, sweet Italian variety, which has been attacked by a serious blight the last few years.
Luckily, other forms of basil — there are hundreds of different varieties out there — are not affected by the blight. And, basil grows quickly.
My advice is to pull out the blasted plants and toss them, along with the top inch of soil they were growing in. Then, sow fresh basil seed in different containers. If September and October are nice and warm, you should get a good late harvest.
Perfect time to sow several crops from seed
Linda in Rockville appears to have fallen prey to basil blight, a fast-moving pathogen that wipes out plantings of Italian, large-leaf sweet basil, by far the most popular variety. But the hundreds of other varieties of basil are unaffected, and basil grows fast in the warm soils of late summer, meaning there’s still time to sow a nice, late crop. Grow it in a different spot just to be safe.
And the places where the blighted basil went bust? Toss the dead plants and the top inch of soil, add some fresh potting mix to the surface and thickly sow the seeds of a leafy, salad green mix. The plants should germinate fast and be tall enough to cut with scissors as “baby greens” in a month. Leave an inch of growth on top when you cut and they’ll regrow for another run (“cut and come again” style), which should be ready right around Halloween.
As Shakespeare wrote, sewage sludge by any name still …
Bob in Wardensville, West Virginia, writes: “Adrian Higgins recently wrote in The Washington Post about treated sewage being turned into compost for gardens. I’d like to hear what you think about this.”
The actual process of using human waste as fertilizer (dubbed ‘night soil’) goes back millennia, Bob (see the classic book about early Chinese agriculture, “Farmers of Forty Centuries”). And modern wastewater plants have been treating and marketing their sewage sludge as fertilizer for decades under the euphemism biosolids. Sounds so much nicer than sludge, doesn’t it?
But unlike ancient night soil, the original raw material for this stuff did not just come out of people. The incoming water these big plants treat can be heavily contaminated by industrial waste and by people pouring things, such as used motor oil, down their toilets.
The heavy metals that survive the treatment process are the one, big reason biosolids are not allowed for use in certified organic agriculture. The treatment process, however, is very good at getting rid of E.coli and other pathogens.
Although an independent analysis shows that everything is under the established Environmental Protection Agency limits, the product that Adrian wrote about, Bloom, from D.C.’s Blue Plains plant, still contains what I consider to be disturbing levels of arsenic, copper, lead and zinc.
Luckily, there’s plenty of good, old yard waste compost to be had in bulk that do not carry these concerns. And, there’s an emerging market of using biosolids for fuel instead of food, which makes good sense to me.
Fall into lawn care
As summer becomes fall, it’s prime time for correct lawn care.
- If your cool-season lawn drains poorly, this is the perfect time to have it core-aerated with a machine that pulls out little plugs to reduce soil compaction. Note: Just poking holes in the lawn won’t do it; you have to remove plugs to improve drainage.
- This is also the perfect time of year to install a new cool-season lawn of fescue or bluegrass by seed, or to overseed a fescue lawn that shows some bare spots.
- It’s time for the biggest feeding of the year for cool-season lawns. The best food is a top dressing of yard-waste compost, such as Maryland’s LeafGro. Corn gluten meal and bagged organic fertilizers labeled for use on lawns are also ideal.
- But no chemical fertilizers. The lush, rapid growth they cause can weaken the turf for winter.
Note: This advice is only for cool-season lawns. If you have a warm-season turf like zoysia or Bermuda, you’d do these chores in the spring.
Mike McGrath was Editor-in-Chief of ORGANIC GARDENING magazine from 1990 through 1997. He has been the host of the nationally syndicated Public Radio show “You Bet Your Garden” since 1998 and Garden Editor for WTOP since 1999. Send him your garden or pest control questions at MikeMcG@PTD.net.
