Author:Erica

Disease-Resistant Vegetables and How to Find Them

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I mentioned in my post last month that many of the pepper plants I grew from seed this year were infected by bacterial leaf spot. I did my best to remove diseased material from the garden, but undoubtedly some of it still lingers in the soil and might survive to infect plants next year, so I will plan to grow varieties that are resistant to this disease.

Pepper leaves infected by bacterial leaf spot. Photo from HGIC.

And no, I don’t just have a list of these varieties in my head. I’ll have to do some research. Maybe you’ve faced this problem too, when all or some of your tomatoes or squash or some other vegetable succumbed to a disease you managed to get identified—and your friendly Master Gardener or Extension specialist advised you to plant resistant varieties. How do you go about finding them?

First, check out Cornell Cooperative Extension’s Disease Resistant Vegetable Varieties page. Here you can find a list for each of many common vegetables of available varieties and the diseases to which they’re resistant. For example, if you have a problem with fusarium wilt in tomatoes, click on Tomato and then skim down the list to note all the varieties with fusarium wilt resistance. (Lucky you; there are lots.) You can also download the information in spreadsheet form for easy reference.

If you have favorite seed catalogs, they can be another good source. Most seed catalogs will add codes to each variety listing that represent disease resistance; for example, fusarium wilt is coded as “F” and if you see “F1-2” that means it’s resistant to both races 1 and 2 of fusarium. (The more resistance, the better, since you probably don’t know which race infected your plants.) Somewhere in the catalog section for each vegetable there will be a list of codes and what they mean.

If you don’t grow your own plants from seed, use these resources anyway. Make a list of resistant varieties, find a garden center or other plant source with a wide selection, and pick out the plants that meet your criteria. Make sure the plants you select look healthy!

Here are some other things to keep in mind:

  • Hybrid varieties are more likely than heirloom or other open-pollinated varieties to have demonstrated disease resistance. If you have anecdotal evidence that an heirloom is pretty resistant, try it out, but you might want to grow it separately from your bed of resistant types. Same goes with that variety you just have to grow because you can’t do without it, but you suspect it may come down with the bug—grow it away from the others.
  • “Disease resistant” does not mean “can’t possibly get the disease.” If the pathogen is present, it will probably still infect plants, but the resistant plants will stay healthy much longer—maybe until the very end of the season, if you’re lucky.
  • Know the source of your pathogen: is it present in the soil, or will it reappear blown in on the wind, or is it more likely to come from infected seed or plant material? Knowing a bit about how transmission works will help you strategize to keep plants healthy. The HGIC website is a good source for information about plant diseases and how they spread (hint: look at the entry for the vegetable and it will list relevant diseases).
  • There may be other methods available to keep disease away, such as treating seeds with bleach or hot water, using fungicides, and most importantly keeping soil around plants covered with mulch to prevent splashing onto leaves. Also try to avoid overhead watering; water at the base of the plant. You can also remove and destroy infected plant parts when you spot them. Using these methods in combination with planting resistant varieties will increase your odds of success.

Do your research and have a bountiful, disease-free growing season next year!

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

There’s Always Next Year

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If I look back at this summer in the vegetable garden objectively, I’d say it was an average success. My garden produced a fair number of tomatoes, peppers, squash and cucumbers. We ate well. But it felt like a really hard year, and I don’t think I’m alone in that experience. We had some nasty heat waves and dry spells, and the plants and produce seemed extra susceptible to damage. I had more cracking and insect damage on my tomatoes than usual, and the plants gave up early due to all the fungal disease. Squash collapsed from vine borers and cucumbers got all the blights. My peppers were the biggest disappointment, battling bacterial leaf spot both in my own beds and at the Derwood Demo Garden. I think some infected seed was to blame, since a few ‘Big Red’ plants were the first to show symptoms, but the disease spread quickly to all the rest.

I’m very invested in gardening, so I’m not going to give up even though I know the struggles are likely to continue; our climate issues aren’t going to get any better and the bugs and diseases are here to stay. I don’t think you should give up either! But I can see how a beginner might feel very daunted.

Here are a few ideas about making your garden less exhausting and more rewarding. I’m writing them down because I need to read them as much as anyone!

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The Ripeness is All (or Some)

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As Dr. Spock famously said about parenting: “Trust yourself. You know more than you think you do.” This is equally true about gardening, even for beginners. People sometimes ask me when they should pick vegetables, as if it was a total mystery, and I generally reply that they’ll know it when they see it, especially if it’s a crop that’s commonly available in markets and grocery stores. If not, a quick online search or a look at the seed packet or catalog may enlighten you. Yours may not achieve the shiny perfection of the catalog models, but it’ll be recognizable. There are exceptions to this easy-to-tell model (melons are notoriously enigmatic) but mostly it’s not so hard.

Being ready to pick and eat, however, is not the same thing as being ripe, and this is a matter of great confusion among even some experienced gardeners, so I’ll plant a few ideas here that might help. Or make you more confused. I don’t know, I can’t think in this heat either.

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Tiny tomatoes perfect for patios (and canine companions)

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Just a quick post this month to shout out the virtues of the first tomato plant to produce ripe fruit for me this year: ‘Veranda Red’ patio tomato.

This little cutie is only 18 inches high, and in fact would be shorter if it was growing in full sun instead of the partial sun on my deck. I have other plants with green fruit ready to turn red that are less than a foot high, and the container team at the Derwood Demo Garden has a plant only about six inches high that has ripe fruit.

Patio tomatoes as a group mature at less than two feet, and grow well in smaller containers like window boxes or gallon pots. The larger the pot, the larger and more productive the plant will be, but they will be loaded with flowers and fruit even in a small container. Most varieties are cherries, though a few make larger salad tomatoes.

‘Veranda Red’ is a relatively recent hybrid, but some patio tomatoes have been around for years. A few varieties I found in a quick search include ‘Tiny Tim,’ ‘Micro Tom,’ ‘Tumbling Tom’ (and the rest of the Tumbling series), ‘Orange Hat,’ the ‘Patio Choice’ series, ‘Red Robin,’ and there are many others. Try doing a search on ‘patio tomato’ or ‘micro dwarf tomato,’ or check your favorite seed catalog. You may also find plants at a garden center (I know Bonnie Plants has their own variety and others are likely available – just read the tags carefully to make sure you’re getting a dwarf plant).

These tomatoes are a great option for folks who don’t have much growing space, maybe a balcony or window box or a postage-stamp sunny patio or yard. They don’t produce as much as a full-size plant, but more than you would think!

Now, I have a bunch of full-size tomato plants already growing in my community garden plot, none of which have ripe fruit yet, but they’re getting there. Why bother with patio tomatoes? Well, sometimes a plant, like a person or a pet, just fills a particular spot in your life. Fifteen months ago I inherited a cocker spaniel named Freckles who used to belong to my mom and stepfather. She’s made a new home with us and definitely found a home in our hearts. Freckles loves many fruits and vegetables and is especially fond of tomatoes – she can sniff out the plants well before they have any fruit and will drag us to them. Last year she hunted for fallen cherry tomatoes around our neighbor’s big potted plants and alerted me to some volunteers that sprouted in unexpected spots in my landscape. So I thought it would be nice if she had her own tomato plants closer to home. We make a stop on the deck after a walk to see if any new ‘Veranda Red’ cherries have appeared. She approves!

By the way, I did get to eat one of the tomatoes myself, and can report that it was very tasty. Recommended, even if you don’t have a tomato-eating dog.

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

Scary Bugs (And Why You Shouldn’t Be Afraid)

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Eek! It’s a bug!

I know most folks don’t like creepy-crawlies. Bugs aren’t their thing. Mine, yes, but this is what I do – help people deal with garden pests and protect good bugs.

Some good guys do look scary, like something out of a sci-fi movie with spikes and fangs and ridges and crazy colors.   

But looks aren’t everything. In most cases, these are good bugs – what we call beneficial insects – that help to control the few bad dudes in your garden.  

Let me introduce you to a few bug friends that aren’t beauties but do a beautiful job of controlling harmful pests.  

Assassin bugs get a bad rap simply because of their name. We’re talking James Bond, right?  

an assassin bug is a cloudy-gray color with a hump on its back
Scary-looking assassin bugs are efficient predators. Photo: Photo: Johnny N. Dell, Bugwood.org 

That’s a good thing. Assassin bugs are efficient predators, but boy, do they look scary. Battleship grey with spikes down their backs, they look like they’re wearing armor.  

But the battle is mostly one-sided. Insects that cross an assassin bug’s path likely will get skewered by its lance-like mouthpart and slurped dry.  

Stop shuddering. There’s an upside. 

Assassin bugs eat almost any bug, making them ecological balancers that keep insect populations in check. Plus, they enjoy snacking on Japanese beetles, the scourge of many a garden.

Cute and beneficial, the ladybug lies at the other end of the beauty spectrum. But as youngsters, ladybugs resemble tiny orange and black alligators which often get squished because they look like they are Up To No Good.  

a lady bug larva is black and organge and resembles a miniature alligator
Spiky ladybug larvae control aphids and other pests. Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

Not true. These are good guys who consume even more aphids, spider mites, scales, and other baddies than adult ladybugs. In fact, one ladybug can eat over 5,000 aphids in its lifetime. 

Many juvenile insects look nothing like their more familiar adult counterparts. So stop before you squish or spray. Snap a photo or bring a sample to your local Extension office. Most likely it’s an ally you want to protect.  

You can find your Maryland Extension office on our website. Or reach out to the certified horticulturists at our Home & Garden Information Center for help. Send a photo or question to them at Ask Extension.

Wasps get a bad rap, too, with much swatting and shrieking and fear of The Stinger. Only females have those – they’re modified egg-laying organs – and they aren’t likely to use them unless threatened.  

But most wasps are beneficial, preying on bad bugs or laying their eggs on them to feed their young. Plus, they are pollinators, protecting 1 in 3 bites of food we eat. 

a wasp visiting a white-flowering plant
Scoliid wasps lay their eggs on Japanese beetle larva. Photo: Shanon Wolf

Spiders aren’t insects – they have 8 legs, not 6 – but they give many people the willies. But spiders also are beneficial, quietly and efficiently consuming many harmful insects.  

a black and yellow garden spider in its web
Argiope spiders provide free pest control in the garden. Photo: Heather Lawhead

Beauty isn’t everything. An army of not-so-lovely-but-useful insects are your allies in the garden, protecting your plants from the 1 in 10 bugs that are actually harmful. 

So think before you squish or spray. Get us a photo or sample. We’ll identify it and give you management tips that deal swiftly with bad bugs while protecting beneficial insects. 

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.

This article was previously published by Herald-Mail Media. Read more by Annette.

Stress and Injury in the Garden

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You’re in the garden on a hot, sunny day. You haven’t had enough to eat or drink, and you’re really hungry and thirsty, though you feel that if you eat anything you might get sick. You’re getting sunburned here and there, and the rest of you is unnaturally pale and weak. Probably you shouldn’t be in the garden at all—look how weird and variable the weather’s been! Speaking of which, here comes a storm. You can’t get to shelter, and there’s rain everywhere; accidents are bound to happen, and yes, before you know it—snap!! Something’s broken.

Call 911! Or maybe not. The question in this scenario is: are you a gardener, or are you a plant?

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Breaking the Rules For Hardening Off

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You won’t find a lot of experienced gardeners—at least those who are honest with themselves—talking about “rules” in gardening. That’s because, strictly speaking, there are very few of them. There are certainly guidelines, which are created through a combination of experimentation, synthesis of results, lots of mistakes and corrections, and effective communication of principles. There’s also a lot of bad advice out there, which you can weed out in simple ways (try using “Extension” as part of your web searches) or by disregarding those helpful nuggets that use only anecdote or tradition as rationales. (“This happened to me once, so it must always be true!” “My grandmother always said…”) Personally, I think you can also ignore pundits who declare rules without exceptions. There are always exceptions.

Or maybe I’m saying that because I just broke a rule. It’s May, so time for hardening off seedlings. The guideline for hardening off is to introduce your young plants to the outdoors gradually. Carry your tray full of pots outside and put them in a sheltered spot (out of the wind and sun). Give them a few hours of outdoor conditions and then bring them inside again. Next day, lengthen the time outdoors. Over a week, expose the plants to more sun and some light breezes. Leave them outside overnight on the last few nights before you plant them in the garden. This way, they don’t get shocked by a sudden change in exposure, and they will settle into their new life more readily. Failure to make this gradual transition could result in a serious growth setback, or even in death. (Of the plant. You’ll be fine, I hope.)

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