Garden Plot: Troublesome tomatoes, compost conundrums and fruit

Meet Mike on Oct. 4 and 5 in Leesburg

She’s got the green tamata blues

Jennifer in Burtonsville writes: “I have two grow boxes of tomato plants on my patio that get about four to five hours of sun a day. The plants are humongous and all tangled together with dozens of big tomatoes hidden deep within the vines — but the tomatoes are all green. Shouldn’t they be turning red by now? I am concerned that they might not turn if the fruit itself doesn’t get direct sunlight.”

You’ve got that backwards, Jenn: Fruits can’t process sunlight. Only leaves have the power to photosynthesize and send the resulting nutrients to the fruits. In fact, too much direct sunlight can ruin ripe tomatoes.

Now, your problems are threefold:

1. Tomatoes need six to eight hours of sun a day. The fact that your sun- starved plants are even healthy is a total mitzvah. Next year, plant them in a much sunnier spot. More sun = more photosynthesis = faster ripening.
2. They sound very overcrowded. Container grown tomatoes do best with one plant per pot. When tomato roots encounter the roots of other tomatoes, everybody slows down, as the plants “know” that their resources are limited by competition.
3. Really big fruits, such as beefsteaks, and “bragging rights” heirlooms, such as Brandywine and Mortgage Lifter, normally take three months to ripen from transplant. And that’s after the weather gets warm. So figure all of June, July and August before ripeness can be expected. Next year, plant a few varieties with shorter “days to maturity” periods. Sixty- to 75-day tomatoes are the ones people are eating in July and August.

Luckily, you can push yours along a little faster by pulling off any new flowers and really tiny fruits. Those flowers and baby fruits won’t have time to achieve full size before frost, and their absence will direct the plants’ energy to ripening up your greenies.

Compost your lawn

Lee, across the water in Easton, Maryland, writes: “Would my lawn or any of my shrubs and perennials benefit from fall composting?”

The short answer, Lee, is yes, yes and yes.

Unlike chemical fertilizers, which would stimulate new growth and damage your plants as they’re trying to go dormant, a 1- to 2-inch mulch of compost applied around permanent plants at this time of year will provide some nice winter insulation for their roots, which is crucial if we get a frigidly cold winter without protective snow cover. And the compost will be there to provide gentle, natural feedings when the plants reawaken in the spring.

And raking an inch of compost into a lawn provides the most perfect fall feeding you could ever hope to give your turf. Lawns that are fed compost in the fall stay the greenest during heat waves in the summer.

This weed tree is a princess — of pain

Bob in Bethesda writes: “A plant that resembles a sunflower has suddenly appeared in my yard. It has grown 10 feet in about five weeks, and has leaves that are more than a foot wide each. We call it the Jurassic Park plant. I have gone online and the closest I can come to an ID is Paulownia. This does not seem correct, because when I Google that plant, I see a tree with small leaves and flowers. It is relatively common here, but is treated as a weed by everyone, as you only see it in untended areas.”

Your ID is correct, Bobalouie. Those huge, heart-shaped leaves and almost impossibly rapid growth are totally characteristic of the infamous “Princess Tree,” Paulownia tomentosa, an invasive plant from Asia sold here as a fast-growing flowering ornamental.

It is indeed the fastest-growing tree in the world, and the flowers on specimens that are left to grow large are magnificent — but it is also one of the most brittle, short-lived and rampantly invasive of all trees. Cut it down before it gets any bigger and dig out the whole root system, or new suckers will sprout to torment you for years to come.

Oh, and the reason you didn’t recognize it is that there are several species in the genus, including ones with much smaller leaves. And your species also looks very different as a baby. Search an image gallery and you’ll see your cute little Triffid in there.

Crazy About Fruit!

Nick in Pasadena (the one in Maryland) writes: “I’d like to plant nanking cherry, grape vines, blueberries and alpine strawberries. Can you recommend a reputable online nursery for the cherry trees and blueberries? What grapes would grow best in my area? And should I just start the alpine strawberries from seed?”

Yes, Nick. Alpine strawberries — little flavor bombs that grow in rapidly expanding perennial clumps — are grown from seed. You can sow the seeds directly in early June and get the first fruits a few months later. Or, if you have the right equipment, start them indoors in March (like tomatoes) and transplant them at the end of May. You’ll be picking by the 4th of July.

Nanking cherry and blueberries are fairly low-care. Their biggest issues are keeping birds away from the tasty fruits. But instead of mail order, I urge you to get the plants locally at a big independent garden center or nursery. But don’t get them at a big-box store.

Grape vines, however, require a lot of room, pretty involved trellising and constant care. Do some research on the workload involved before you commit to these time-consuming fruits.

Your honey-do checklist for September

It’s time to:

• Patch bare spots in your lawn with matching seed.
• Sow seed for a brand-new lawn — but don’t delay!
• Provide your lawn with a safe, natural fall feeding: compost, corn gluten meal or a bagged organic fertilizer designed for use on lawn.
• Improve the drainage of lawns growing in compacted soil by having plugs removed with a core aerator.
• Plant single cloves of locally grown garlic to harvest big, beautiful bulbs next summer.
• Plant pansies for live outdoor color (and nutritious edible flowers for salad adornment) for months to come.
• Grow lettuce and spinach and the sweetest carrots you will ever taste.
• Pot up your begonias and bring them inside, where they’ll bloom all winter in a sunny windowsill.

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