It’s the beginning of May, so it’s time for my annual appeal to hold off on planting out your tomatoes and other cold-sensitive crops. I think the plea may fall on deaf ears this year, because looking ahead at the 10-day forecast here in upper Montgomery County, I see only one night that might fall below 50 degrees F., and only barely below. Days are nice and warm. It feels like tomato-planting time.
Let’s just state a few caveats, though, and then I’ll let you go about your business.
In many recent years, we’ve had a substantial drop in temperature in mid-May, even after summerlike conditions had already taken hold. That may not happen this year, but it still could.
It looks like we are finally going to get some rain coming up—hurray!! We really need it. But a rainy period isn’t the best time to put tomatoes in the ground, not because you get wet, but because the plants do. Wet leaves and splashing mud will make them more susceptible to fungal diseases that could be lurking in the soil. If you do plant during or before a lot of rain, make sure the soil is covered by mulch.
Most importantly, the air temperature at planting time matters less than the soil temperature, and at least where I’m measuring, the soil temperature is far below the ideal 60 degrees F. that tomatoes prefer. Get yourself a soil/compost thermometer and stick it in the ground where you intend to plant; see for yourself. Cold soil temperatures hold back the growth of plants that like it warm, and fruit may be poorly formed.
My tomato and pepper plants are still inside under lights. They’ll venture outside to start hardening off this weekend, so that in another week or so, if the forecast looks good, I’ll be able to consider putting them in the ground. But I’m definitely going to check that forecast and stick that thermometer in the soil.
If you’re in a hurry, and are ready to jump in and protect your plants if we have a mid-May frost, I can’t stop you from planting. You may end up with plants that produce much earlier than mine. Or they may sulk and get diseases and make misshapen fruit. Sometimes the bet pays off, and sometimes it doesn’t. I like to play it safe.
By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.
One of the most common questions asked by novice vegetable and herb gardeners is “How many?” That is, how many of each plant to put in, so that the harvest will be enough to make dinner but not so much that you’re frantically trying to find homes for a major surplus. When you plan an ornamental border, there are design guidelines that talk about groups and masses and specimen plants, but food gardens (although they can be beautiful) are not planted with aesthetics primarily in mind. So how to make these choices?
You can find plenty of guides online for, say, planning a garden for a family of four. These tend to assume that your garden is large and that you want to supply all or most of your needs from it. Which is great if that’s your goal, but I don’t find that many of the busy urban and suburban gardeners I talk to mean to skip the supermarket produce section entirely. The online guides will also measure the planting in feet of row; if you grow in the square footage of raised beds, you’ll have to do some recalculation. Growing in these kinds of high volumes probably also requires food preservation, whether by freezing, canning, or some other method.
Your garden does not need to be planted in long, long rows to be productive
Most of us find the answer to “How many?” through trial and error, and frankly you probably can’t avoid that entirely. You’ll err on the side of not enough for some plants, and too much for others, and will serve some salads featuring a handful of lettuce or one small cucumber, or get to know your neighbors when you have tons of extra tomatoes. But there are ways to plan.
This could be a great year to get an herb garden started! We have lots of information on the HGIC website about growing herbs, and more will be coming soon to celebrate GIEI’s Year of Herbs. I’m going to add here some hints for making your herb garden a success.
Note: this information is about culinary herbs (plants whose leaves or seeds are used as seasonings) rather than medicinal herbs, which are used to treat medical conditions or promote health. We here at Grow It Eat It are not medical practitioners and cannot recommend medicinal herbs for use, though we could give you some ideas about growing them. Please don’t experiment on yourself based on random information gleaned from the web or an old book. If you want up-to-date advice about herbs and your health, contact a herbalist who’s part of the American Herbalist Guild. The Herb Society of America also has reliable information about all sorts of herbs on their website.
The first thing to ask yourself about starting a culinary herb garden is which herbs you enjoy using in your cooking. If you’ve bought fresh herbs at a grocery store, you know how expensive they can be, and often the bunch is too big for you to use up before they go bad. Think about having all the herbal bounty you want, when you want it, for the cost of a few dollars to buy a plant or some seeds!
Chives are one of the best perennial herbs to add to your garden
Where to find plants and seeds
First, while those little pots of herbs you buy at a supermarket are useful to have around in your kitchen in the wintertime, they do not transplant well to the garden. It looks like they are grown by putting a bunch of seeds into a pot and creating lots of skinny plants that will not be healthy enough to survive moving, plus they have never been exposed to outdoor conditions. Buy your plants from a garden center and check to make sure there are not more than two or three at the most in the pot—one would be better, even if it sounds less cost-effective.
Many garden centers and hardware stores stock herb plants in the spring. They often come in various pot sizes, and unless for some reason you need a big plant immediately, you’re better off starting with a small one and giving it good growing conditions. Make sure the soil in the pot isn’t bone-dry (or soggy wet) and the plant isn’t losing leaves, turning yellow, being chewed on by insects, or mysteriously spotted or ragged. In other words, it should be healthy! Try to buy early rather than waiting until the last pathetic bits of inventory are on sale.
You can also start herb plants from seed, but check first how long they will take to grow. You may be better off starting with a plant someone else has grown. The HGIC website page linked above will give you specific advice.
If you’re looking for something more unusual than the commonly available herb plants, you may need to order a plant or seeds online, or visit an herb fair in your area.
Where to plant your herb garden
First, make sure you know whether each herb you’re planting is an annual, biennial, or perennial. Biennial plants (that bloom and go to seed in their second year) and perennial plants (that last for at least several years) require more thought in placement than annuals, which can essentially be treated like annual vegetables. You can put herbs into your vegetable garden, but if they are going to be left in place over the winter, it makes more sense to locate them on the edges or in their own sector, so the roots won’t be disturbed by digging. Or you can plant a separate herb garden, or grow your herbs in containers.
Basil comes in many types and fits well into your vegetable garden
The most important factors in growing herbs are sun exposure (most herbs want full sun) and good soil drainage. Most herbs don’t need highly fertile soil, but they do react badly to heavy clay soils that hold water. Consider creating a raised bed for herbs, since it will drain much better.
I’m giving advice about “herbs” generally, but each type of herb has its own growing requirements and habits, so check out the HGIC page and the Herb Society of America website for more specific information. Some herbs, like basil, want more watering, grow fast and need frequent harvesting; some, like lavender, grow more slowly and prefer rocky, drier soil, but can eventually become monsters that take over your entire designated herb area.
Lavender can get very large, and you may not use a lot of it in your cooking, but it’s beautiful, fragrant, and a great plant for attracting pollinators
Other considerations
Give some thought to how many plants of each herb you need before you start buying. You may want multiple basil plants if you plan to make pesto, for example, but you will really never need more than one culinary sage plant.
Some herbs will multiply given the chance, either by dropping seeds or by insinuating their roots into every corner of your garden. Be careful with the mints, always! But it can be nice to have cilantro and dill plants springing up here and there.
Herbs are not just for your meals. Many herb plants are extremely ornamental and can be grown as part of flowerbeds (assuming the soil and light conditions suit them), or might add some pizzazz to your vegetable beds. The flowers are often beautiful and attract insects that will pollinate your other plants and/or protect them from pests. Strongly scented herbs may also have some deterrent effect against animals like deer and rabbits, although it’s better to rely on a fence.
Just be aware that growing herb plants is addictive! But your meals will be better for it.
I’ll post more about herb growing in the coming months. Spring is approaching fast!
By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.
2025 will be Grow It Eat It’s Year of Herbs! So I thought I’d look forward to the coming year by featuring some seasonal flavors. No, not pumpkin spice. We can grow some of the aromatic, usually seed-based spice plants in our region, but many of them (such as cinnamon and nutmeg) require a very different climate with year-round warmth. Herbs, which are usually leaf-based, are much easier. Two garden favorites are also popular at this time of year in food, drink, and special treats. Let’s talk about rosemary and peppermint.
Rosemary, looking fine in December
Maybe we think about rosemary in December because of those sheared “Christmas trees” you can buy in stores and take home as a holiday centerpiece. I would not count on having those live very long, though they are pretty and fragrant for as long as they last. Rosemary doesn’t like the warm dry air inside our homes, and it’s hard to keep potted rosemary watered well enough not to dry out while still not rotting its roots. Rosemary is one of the Mediterranean herbs that evolved to grow in rocky soil near the sea, which is not a climate that exists in your dining room. It doesn’t really exist in central Maryland gardens, either, but I’ve managed to keep rosemary going for a few years at a time by giving it well-drained soil (gravelly is great, but raised bed soil will work), full sun, and protection from winter winds. Rosemary has a reputation for dying in cold winters, but the factors that really kill it off, from my observations, are sudden plunges in temperature, wild temperature fluctuations in general, and too much moisture at the root level. If you know there’s an Arctic air mass coming, you can try temporarily wrapping the plant – don’t leave it that way all winter, though. It’s tougher than you think.
Rosemary is a great way to give your meals a wintry, pine-foresty flavor. It’s used in meat dishes and with roasted vegetables, and in stews and baked goods. If you take care of your outdoor plants, you can harvest from them all year long; rosemary is an evergreen herb as long as you treat it right.
Mint growing in a pot outside a house. By Sunnysingh22/Wikipedia.
Peppermint is another garden plant with a reputation, and in this case it’s well-deserved. Mints spread vigorously by root runners, and will happily take over your entire garden if you let them. Peppermint is one of the worst offenders. If you want to grow it – and you should, because it’s a great flavor element to have handy – grow it in a container, preferably close to your house, like on a deck or patio or front stoop. If you do plant it in the ground (and I did this, because I wanted more than would grow in a pot), make sure it’s in a location where the root growth will be constrained by pavement. It will still become a ground cover in that area, but walking on mint and releasing its scent can be very pleasant. I’ve been able to keep mine more or less under control, with some aggressive weeding. But I previously had horrible experiences with mint in (or near) vegetable gardens, so… just don’t. It will even escape from a pot through the hole in the bottom and start growing into the soil underneath, so put those pots on impermeable surfaces.
If you are going to grow peppermint, start by buying a plant. Peppermint (Mentha x piperitai) is a hybrid of two species of mint, and therefore doesn’t come true from seed (in fact it seldom produces seeds). In general, it’s easier to buy herb plants rather than growing them from seed; rosemary, for example, will grow from seed, but it takes a looong time. Let someone else do the work!
Peppermint can be used in flavoring meat and vegetable dishes, especially Middle Eastern ones, and to make wonderful herbal teas. Spearmint is a better choice for cocktails and refreshing cold drinks. (Same planting considerations; spearmint is also a great spreader.) When we think of peppermint in December, it’s mostly because of candy canes and other sweet treats, including peppermint-flavored cocoa and chocolates. You probably won’t make those from your own garden peppermint (which tends to die back some in the winter anyway, though it will usually come back in spring if given some protection from freezing winds), but if you’re interested in where they came from, try this recent episode about mint from one of my favorite podcasts, Gastropod. The discussion focuses on the commercial uses of peppermint and how they developed over the last few centuries, and it’s a great listen.
Both peppermint and rosemary are in the mint family, as are many of the other culinary herbs we prize in our gardens. In this upcoming Year of Herbs we’ll post a lot about how to grow and use those and many others. In the meantime here’s a post on herbs in veggie gardens I wrote a few years ago – start planning now!
Happy holidays and best wishes for a fragrant winter season!
By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.
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.
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!
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.
