entertainingFood & Drinkweeders digest

weeder’s digest: tomatoes

by Grace Bonney

Hopefully someday I’ll be fortunate enough to have a real garden where I can spread my wings and grow 25 varieties of heirloom tomatoes, flowers like my friend Alice and black currants…but until that day comes my modest fertile crescent exists on a few cubic yards of Brooklyn sidewalk. The City has me in chains, and each spring I’m happy to throw it a few seeds and hope something grows up from its cracks.

This year I have some nice looking tomatoes. How are your tomatoes? Really? Wow. That big already huh…
OK FINE! I have a few problems – namely powdery mildew. It’s common enough. My plants look healthy with lots of blossoms and small fruits, but there’s a dusty white film in small circles on the leaves. Innocent enough looking – if left untreated the leaves will start to yellow and corrode…by the end of August the whole lot will be a crispy mess with stunted fruits. No victory in that garden.

I’ve mentioned home remedy’s for bug infestations here before – I really feel like most every plant ailment can be treated with simple concoctions of pantry items – especially if you’re growing on a smaller scale. I’m treating my mold with a homemade fungicide:

1 Tablespoon of baking soda
2 Tablespoons of canola oil
1 Teaspoon of liquid-soap like Dr. Bronners
1 Gallon of water

Hose off your infected plants first, then give a good spray. I spray the leaves and the soil. Always spray in the evening, after the sun has set so you’re treated leaves don’t “burn” in the heat of mid-day sun.

If you’re tomatoes have other ailments maybe we can sort out a good remedy for you in the comments…and also I want to mention something a bit more serious called Late Blight that seems to be affecting tomatoes in the North East. Characterized by “white, powdery spores; large olive green or brown spots on leaves; and brown or open lesions on the stems.” Read about it here.

Some powdery mildew on leaves

Healthy rooftop tomatoes

Advanced mildew

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  • Those look pretty healthy to me. We just have the blazing Dallas sun to contend with. What varietal(s) are you growing? Are those heirlooms?

  • Actually, another good remedy for mildew is milk. One part milk to 9 parts water, and just spray it on the leaves. Voila!

  • A good source for natural remedies and tips is Ed Lawrences’ Gardening Grief and Glory. He’s a weekly guest on Canada’s public broadcaster CBC radio.

    An easy variety to grow that yields a ton of tomatoes early and all season long is Golden Honey Bunch. They’re not heirloom, but they’re tasty and plentiful!

  • yes! the milk works as well!
    and shannon I agree that a great variety for city gardeners is a yellow cherry tomato – we have yellow pears that do very well in pots and produce tons of fruit from late july through august. (thats the variety you see in the roof-top photo. the top photo of the healthy tomatoes are Korean Love Apples)

  • Yes, do the milk. I’ve wrestled powdery mildew on my zucchini plants in years past and after cutting off the most damaged leaves I spray with milk. Also, it helps to keep consistent moisture levels in the soil (rather than dry, wet, dry, wet. . .) and smashed up egg shells in the soil as well. Always water from the bottom. This helps prevent the spread of the mildew as well as maintaining good air flow through the leaves.
    Hope that helps!

  • Interesting. Tomatoes do best if they are watered every other day or so (to encourage strong roots), and then properly soaked rather than just a light sprinkling, and as Margaret said watering from the bottom is best.

    Can I also be a total pedant and say that some of the grammar was a little haywire (you’re instead of your) and (remedy’s instead of remedies)? sorry to be a bore but stuff like that always leaps out at me.

  • Thanks for all the tips. Glad to hear that you can grow tomatoes even if you are in NYC!
    Margaret: “Always water from the bottom”??? Can you explain please?


  • Thanks for all the tips! Glad that you are still able to grow some tomatoes even in NYC! :)
    Margaret: “always water from the bottom” ? Can you explain please?

  • I’ve tried the super natural remedies but the fungus is a troublesome one. At Chelsea garden center yesterday they had me get some “natural” (ha) copper dust. Instead of putting on the leaves and/or spraying, she told me to put right on the soil. The problem is the fungus is in the soil and only shows up on the leaves. I was also told to cut off all leaves showing the fungus, it does spread that way as well. Just day 2 into the process. I’ll let you know what happens.

  • I’ve always worried a little about eating stuff that I’ve grown on a city balcony – does anyone know if plants absorb pollution or if they can filter it out?

  • Watering from the bottom means, water the soil not the actual plant itself. The roots are what need the water.

  • This post and the comments are very informative!
    I’m growing yellow pear tomato this year and it’s doing really good. It sits in the sunniest part of my little yard. But my friend’s (same variety, but placed on 3rd floor balcony) just seems to grow and grow into a very tall plant with little fruits. Any body can help with this one?

  • We are having a problem with squirrels and possibly rabbits here in Atlanta. We have five plants that start getting nice big green tomatoes, and then, poof, they vanish without a trace. I’m reluctant to use chemical means because I have a toddler that likes to dig in the garden. Any suggestions?

  • To Helen X: I had a similar problem last year (my first time gardening in an actual yard, not a pot). I think the key to more and bigger fruit is pruning. The extra leaves tend to pull nutrients from the ones that can produce fruit. It’s been working miracles for me. Just posted about this recently: http://bit.ly/16KjV1

  • I thought I was buying a cherry tomato plant this spring, but someone had stuck the plants in the wrong section and the wrong cards in the plants, because what I’ve got are not the sweet 100s I thought I would have.

    That said, I’ve gotten about 4 plum size tomatoes off my plant so far and they’ve been delicious. I water everday, only the soil/roots, because it’s been in the 90s here most of the time.

    The very bottom of my plant has gotten totally yellow leaves and it’s been that way for a minute. I’m going to try the milk.


  • I need tomato help!
    We just moved into a house that has fruit & veg. plants, including 1 tomato plant. I had to bring it back from the dead. Now, there are several small tomatoes all over the plant but they only get a tiny bit bigger, stay shrivled and eventually turn bright red. If you cut into one, they seem like they aren’t fully matured.
    I don’t see any bugs or anything. there are lots of dead crispy leaves around the plant. Anyone know what’s going on?

  • I’ve had the same issue with my tomato plants growing out of control. I have two on my 3rd floor balcony and they have grown over 5 ft. The only problem is they have tons of buds but not much is happening.

    I also have a third one inside my window that gets more sun, it has grown 2 ft in a yogurt container and has tomatoes.

    Are the ones outside possibly not getting enough sun, since they’re partially blocked by a tree parts of the day?

  • I heard on NPR this week that blight has caught a lot of the tomatoes on the north east because of the rainy weather. :(

  • We have real problems with powdery mildew here in NZ too, it’s the humidity! Sadly the really fabulous heirloom tomatoes seem to be particularly prone to it. Another cause of it can be the plants drying out a bit, combined with humidity and poor air circulation. That last photo does look a lot like the beginnings of blight – the first time we had it on our tomatoes we didn’t know what it was and didn’t act on it and within a week the plant was gone. Sometimes they manage to fight on, ending up much as you describe, but you never get much fruit off them and you’re better pulling them out and trying to keep the other plants healthy. Mmmm…fresh garden tomatoes! We’re suffering through hothouse tomatoes at the moment, longing for the return of summer and the first sun-warm tomato sandwiches.

  • Grace, when you say mildew do you mean blight?
    Because if mildew leads to blight, it’s a serious problem, you need to act quickly. I discovered yesterday that one of mine has late blight. That tomato tree had the most fruits (although small), and some of the fruits are turning brown before they are even ripe!
    Today I’m off to the allotment to pull the diseased plant out (you need to burn it to kill the fungus, never compost) and put a clear plastic sheet over them to protect them from rain. Too much rain brings down the fungus pores that are in the air onto the plants and soil. (it’s been a cool& wet summer in London-too wet for vegies)
    Please excuse my long comment…

  • I was a “plant girl” for several years, and we used a simple solution called SWA for plant parasites and powdery mildew. It’s easy to remember the solution: Soap, Water, Alcohol. They never gave me exact measurements for the SWA but I still use a bit of rubbing alcohol, some liquid soap, and then fill the rest of the spray bottle with water, shake up and spray. I spray problem plants once a week but sometimes they only need one treatment, depending on the severity of the parasite/mildew. Make sure you wipe off the mixture to remove any mites, mold spores, etc… then I re-spray after wiping.

  • I use white oil to spray the tomatoes. It is natural and you dilute it with water (a third to 2/3 water) and it works brilliantly for powdery mildew and most other things that ail tomatoes!

  • I’ve used the chamomile tea treatment for powdery mildew on my peonies. Brew up a big batch of chamomile tea (I needed one to two quarts for my four big peonies), and when cool, transfer to spray bottle. Spray leaves generously in the morning. Repeat as necessary. We had a cool and wet summer several years ago, and as I took my evening walk, I noticed everyone else’s peonies had silvery foliage — except mine!