What’s a Determinate?

determinate vs. indeterminate tomatoesIf you ignore the yellowing, early blighted leaves (which were snipped moments after this photo was snapped), you’ll see a still-producing Isis Candy cherry tomato towering above its neighboring Gold Nugget.

It towers because it’s an indeterminate — that is, it keeps going and growing and going. Until diseases finally fell is, that is. The Gold Nugget, one the other hand, has about had its day. It has reached its determined height, produced a couple pounds of tomatoes, and is about to expire.

The determinate vs. indeterminate is an important consideration for gardeners, especially those with limited space. Like, for instance, this particular roof deck gardener.

This year, POD selected two indeterminate varieties (the late Chocolate Cherry and the ailing Isis Candy) and two determinate varieties (Gold Nugget and Tumbling Tom). Because POD’s seduced by the idea of an ever-growing, ever-producing tomato, the larger and ungangly and space-hogging indeterminate is quite fetching. However, because disease is a constant lurking threat, the short(er)-lived and compact determinate has its merits.

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Sap Suckers

Because Early Blight just isn’t enough pestilence for one little blue deck to endure, it’s also got a fascinating case of banded winged whiteflies. What the heck?

Looks like it’s become a race: how many tomatoes can one eat before the tomatoes eat themselves? So far over three pounds have made their way into the kitchen and that feels like an enormous success.

What you see here are the eggs and larvae of the whitefly sucking their way through the underside of a chocolate cherry’s leaf. If you look veerrry closely, you’ll see one of the more mature almost-flies taking a stroll along the lower left edge of the leaf.

bandedwinged whitefly, chocolate cherry
banded winged whitefly, chocolate cherry tomato

These pernicious pests are easy to miss. It took a good deal of staring, research, more staring, picking, squinting, still more research, and then magnifying photos to figure it out. These microscopic suckers live on the undersides of the leaves but the top of the leaf appears to have whitish spots, then suddenly wilts and falls off. All that and they transmit a viral diseases, too.

By all accounts, whiteflies are tough to control. The poor chocolate cherry tomato has been moved as far away as possible from the struggling, but producing, Tumbling Tom, Gold Nugget, and Isis.  POD hates the thought of chemicals (because we actually do want to eat what tomatoes can be salvaged) and kinda’ figures these guys are a lost cause. But, the undersides of the leaves are being hit with all we’ve got: soapy water with baking soda, EcoSmart Organic Garden Insect Killer, and Garden Safe Multi-Purpose Garden Insect Killer. Take that.

Yup, it’s Early Blight

The wonderful Colorado State University Extension provides a terrific online tool for diagnosing a myriad of tomato diseases. Take, for example, the following:

Early Blight, Colorado Sate University Extension image
Early Blight, Colorado Sate University Extension image
POD gold nugget, early blight
Early Blight, POD Gold Nugget

So, okay, POD has Early Blight. No surprise there — it’s a recurring theme on deck.

Yeah, you may have thought you were off the hook. Your tomatoes were thriving and then, suddenly, they weren’t.
Symptoms become more obvious during the hotter months, so June and July spell tomato doom in Philly.

Now, what to do?

  • Prune diseased leaves (as POD does oh-so-conscientiously) but keep an eye out for sunburned fruit. If you have to harvest it early, wrap it in newspaper and it’ll ripen in a few days.
  • Since this is a fungus (soil, wind, or seedborne), sanitation is your best best: Remove all diseased plant leaves from the soil, clean your trimming tools, space your containers judiciously, avoid touching healthy leaves with the sick ones, wash hands before touching healthy plants.
  • At the end of the season, clean and dry containers and drainage materials thoroughly.
  • Use fresh potting soil each year. (POD dumps her used dirt on the local community pocket park…is this bad? No vegetables are grown there, the park desperately needs something besides city-provided wood chip mulch, and it truly hurts to throw the soil away.)
  • Good air circulation is key, but the gusty winds on deck do a good job of ensuring this.
  • Water the soil in the morning — avoid watering the leaves. Philly’s cold, rainy May and June didn’t help with these efforts…at all.
  • If the infestation is heavy, use sulfur dust, Neem, or copper spray — it may help protect new leaves from infection.
  • Fertilize! POD could be much more diligent on this count. Next year, POD’s gonna’ stick a calendar on the fridge and use an organic 5-6-5(ish) fertilizer every couple of week.
  • Demonstrate patience: properly harden-off seedlings, transplant when evenings are consistently over 55 degrees, and trim leaves before sinking them into the soil. Refer to Return of the Fungi.

You’ve Got…the Plague!

Tomato growers, beware! Seems there’s a big bad nasty out there. You know, the little bug that caused the whole Irish Potato Famine? Yeah, it’s back and it’s nasty. Keep close tabs on your tomatoes and potatoes — and don’t be afraid to pitch ’em and start over. Seems plants supplied to big retailers like Lowe’s and the Home Depot were affected. If you planted from seed, you should be okay (for now). Keep your eyes peeled, though, this sucker spreads fast. So far POD’s homegrown plants are free of this particular killer and despite their illnesses, they’re still producing.

For more info: http://www.extension.org/pages/Plant_Disease_Threatens_Tomatoes_and_Potatoes

Return of the Fungi

Stupid tomatoes.

If someone tells you tomatoes are easy to grow. Ignore them. They don’t know what they’re talking about. Then again, maybe they do. Maybe they’re tomato jedi. In that case, listen carefully to their sage advice and then send them this way.

As you can see, some random fungus or another has struck. The cold spring evenings and the torrential May and June rains that Philly suffered didn’t help.  Fusarium or verticillium? Who knows and who cares — the result is the same: sad, sad tomato plants with a low yield. At this point, all that can be done (snipping affected leaves mercilessly) has been done.

Return of the Fungus: 2009
Return of the Fungus: 2009
Nugget's First Haircut
Chocolate Cherry's First Haircut
tomato fungus trimmings
Grrr. Arg.

A glutton for punishment? But of course. Here are a few notes for next year (additional suggestions most welcomed):

  • Shop for disease-resistant varieties — don’t be suckered by heirlooms, as much as you love them.
  • Start the seeds in mid March, using new sterile soil — no earlier!
  • Wash and sterilize containers, purchase new drainage materials.
  • Carefully harden off — no cheating!
  • Plant early to mid-May (strip off the leaves that are submerged in the soil) — no earlier!
  • Spray regularly with Neem and feed them.
  • Continue to mulch, water in the morning, and do the anti-fungus-some-rain-but-not-too-much-warm-but-not-hot-weather dance.

Freakin’ Fungi

Show of hands, please. Who here has watched with horror as the leaves of their formerly healthy tomato plants suddenly turn yellow, cankerous, and then wither up and die? Well, join the club.

Arrgggh!!!
Arrgggh!!! (stock photo, not 2009 POD toms)

Here’s a primer on what POD’s tried and trying.

Supposedly these fungi (early tomato blight, fusarium wilt, and verticillium wilt) spread through contaminated soil or seeds.  So conceivably POD’s initial years of  infections could well have come with the well-started plants. Since new soil is purchased each year,  it’s unlikely contamination comes from the soil. Last year’s disaster is a mystery since the plants were started from seed in fresh soil. Unless, of course, the seeds themselves were contaminated. Hmmmm. The containers weren’t scrubbed clean this year, so perhaps there’s still some cause for concern. Something to remember for next year. We shall see.

Shop Wisely: Look for the following information on your plant’s tag or seed description (it means the variety is resistant to that particular evil disease)A – Alternaria leaf spot, F – Fusarium wilt, FF – Race 1 & Race 2 Fusarium, L – Septoria leaf spot, N – Nematodes, T – Tobacco mosaic virus, V – Verticilium wilt

An apple a day: Keeping plants well fed and happy will increase their resistance to fungus. A little calcium, and a fertilizer solution that’s not too heavy on the nitrogen. Next year we’ll try fish meal and more seaweed but for now, I guiltily confess, very diluted Miracle-Gro Tomato food is doing the job. (The nitrogen seems a little high, so this year I’m diluting it to half the strength they recommend.)

Patience, young Skywalker, patience: Wait until temperatures have stabilized and your seedlings have been properly hardened-off before planting. This increases immunity.

Thirsty Suckers: Tomatoes are 90-95% water and therefore, need water. Containers dry out quickly. Fun times. Don’t be afraid to get dirty. Stick your finger into the soil. Is it dry an inch or two below the surface? Water. Is it wet? Don’t.

Rise and Shine: Watering at night is like sticking a big “Fungus Welcome Here” sign on your tomato. Do it in the morning. Avoid getting water on the leaves. Mulch to avoid splash back. Do not touch the plant when it’s wet. Step away from the tomato.

Fumigate: Okay, POD can’t bear to use industrial fungicides and has been using Neem. Perhaps we’ll brave a baking soda, dish soap, and milk solution this year.

Give ‘em a Buzz Cut: So you’ve practiced your due diligence but suddenly, leaves are turning yellow. Nip ‘em off as soon as they begin to turn yellow. Avoid touching adjacent leaves with the diseased cast-offs. Hope for the best.

No Smoking: Tomatoes don’t like tobacco. Don’t smoke and don’t plant those pretty tobacco flowers anywhere near a tomato.

Tomato Genetics

The lessons learned about tomatoes never seem to end. For example, just the other day POD learned that some heirlooms have a wilty gene. Who knew? Evidently, this simply means you need to water them more frequently than their brethren who lack said gene — perhaps something container gardeners should seek to avoid. And, I see rumors of tomatoes — heirlooms — that are genetically resistant to fungus.

I really, really want these tomatoes.

Does anyone have a list of varietys that do not contain the wilty gene and do contain the two genes responsible for fostering an immunity against fungus?