Cleaning up the vegetable garden in fall

With the first frost of autumn hitting many areas of Maryland, this is a good time to think about cleaning up your vegetable garden, if you haven’t already done so! Below are some hints to getting this job done efficiently and well, and some distinctions between the vegetable garden and the rest of your yard to keep in mind.

First, maybe you still have seasonally-appropriate plants growing – in which case, congratulations! Whether they are cover crops or cool-season vegetables, keep them watered as needed and remove weeds. We’re past the point where you have to worry about most insect pests, so the lightweight summer row covers can come off the brassicas, but you may want to replace them with heavier row covers to keep the plants a bit warmer and protect them from wind. You’ll have less frost damage that way, and can keep your veggies alive longer into the winter.

Summer vegetables, however, are toast. In some recent years we haven’t had frost until later in November, and I’ve seen lots of gardeners keep tomatoes and peppers growing up to Thanksgiving. My attitude is, why bother? You may still get some produce, but the quality and flavor will not be great, and then you’ll have to do cleanup when it’s really cold. Just pull the plug. Of course I have a small garden, and if I want to plant any fall veggies, the summer ones must vacate as soon as they start to go downhill. Your mileage may vary. But it doesn’t seem worthwhile to keep a sorry plant alive for just a couple of cherry tomatoes or a wizened paprika.

So, the first step is getting old plant material out. But wait, you say – didn’t I hear that we should leave plants in the ground until spring for overwintering insects? Sure, but not in the vegetable garden. Here are two good reasons why. First, when you leave perennial plants standing in your landscape so insects can find shelter inside their stems, you commit to waiting until the weather warms in late spring to remove the dead material. That’s going to be too late for vegetable planting in many cases, especially if you rotate crops and are planning to put a spring crop where your summer veggies grew this year. There’s a big difference between a landscape of perennial flowers and an ever-changing garden of annual vegetables.

Secondly, many vegetable plants are great disease hosts. Think about it – if tomatoes and squash didn’t produce delicious food, we’d probably banish them because of how awful they end up looking and how many fungi, bacteria and viruses they spread. The longer that diseased plant material stays in the soil, the more parts drop off and bury themselves, and in some cases that disease lives on until the next year, ready to infect a new host. Ideally you should remove sick plants, or at least the affected parts, as soon as they show disease. This is really hard to do in the middle of the growing and harvesting season, but if you haven’t caught up, at least do it now.

In general, diseased plant material shouldn’t go into home compost. Some fungal diseases will be killed by thorough hot composting, so if you’re rigorous you can take the chance, or else put it on the curb and let your municipal composting do the job. Consult our vegetable diseases pages for information about each type of infection – in some cases, you should just put the plant material in the trash. If you don’t know what infected your plant, it may be best to throw it out. If the plants have been healthy, you can shred and compost them, but remember to not add mature seeds to your compost. We’ve all had pumpkin vines and tomato plants emerge from our pile, and while it’s fun to have volunteers, remember that they may be cross-pollinated and unpredictable in what they’ll produce. Also, don’t add weeds that have gone to seed, or ones that have big roots.

Rake up the surface of your beds; get all that plant debris out. Then, the final step to putting the garden to sleep is covering the soil. If you haven’t planted cover crops, use some kind of organic material to keep the soil from erosion and sprouting weeds. You’ll be surprised how many weeds will cover those beds by spring! Many “winter weeds” have thousands of seeds to spread after they go to flower, so while the bees may appreciate the early snack they provide, you will not. Covering soil also helps to protect the beneficial microorganisms and other critters that inhabit it.

Fall is a great time to add compost to your garden beds, and if the compost is really finished its breaking-down process, it can be used by itself as a mulch. However, it’s probably better to protect it and limit its potential as a weed bed by covering it with other organic materials. Leaves, shredded or un-, are a great option, if you have them around. It’s less important to shred leaves for vegetable garden mulch than for perennial beds; it doesn’t matter that whole leaves mat down and stop young plants from getting through, because you’re going to remove them before planting anyway. Sometimes whole leaves blow away, though, so it’s your choice. Straw is another great option, either from a bale (make sure it’s straw and not hay, to limit the number of grass seeds that will sprout), or in a product often known as “sticky straw” which stays in place better (the “tack” will go away in time and the straw will decay nicely). Don’t make the mistake I did and buy the straw rolls that are held together with netting! Those are meant as a temporary cover for new grass seed. I guess I’ll pull mine up in the spring and maybe I can use the netting to keep the rabbits out of my lettuce bed.

You can also cover beds with a few layers of newspaper and then put leaves or straw on top, if you’re particularly worried about weeds popping up. Whatever lightweight organic material you have will be great, or you can also use black plastic or a roll of weed barrier as a temporary cover if you have nothing else. Plastic keeps the rain away from your soil, however, and it wants the moisture. And when the mosquitoes emerge again, they will breed in the puddles where the plastic isn’t flat.

Finally, fall is a good time to repair fences and fix or add other permanent garden structures. Do it now and you won’t have to do a rush job in the spring.

Then have a nice cup of tea or cocoa and put your feet up!

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

Want Flowers Next Year? Here Are Some Pollinator-friendly Plants to Plant This Fall

Although the end of the summer/early fall may seem like an odd time to think about planting, don’t be fooled! This is actually prime time to allow plants to establish and grow strong for next spring. In fact, planting in the early fall gives time for plants to establish their root system, acclimate to the new conditions, and be ready to grow as soon as the spring conditions become ideal for them to develop. In today’s post, I want to present a couple of very neat plants that can be planted now to bloom and provide resources for next spring’s pollinators. And because these are some plants that are just close to my heart, let me try to convince you to add some (or all! 😊) of these to your green spaces, so you can enjoy them next year. Let’s talk about mountain mints, beardtongues, and Culver’s roots.

Narrow-leaved Mountain Mint – Pycnanthemum tenuifolium

As its name may let you infer, this is a plant that belongs to the mint family (Lamiaceae) and, as a mint, it is very aromatic. The genus is native and restricted only to northern North America, and we are lucky to count several species within Maryland’s native flora. As is the case for most Lamiaceae, mountain mints do not only present beautiful flowers; they have been used traditionally as a food seasoning and in medicinal teas to treat colds, coughs, and fever by many Native American tribes. Although some species are currently protected in the state, some are common, one of which being the narrow-leaved mountain mint (P. tenuifolium) I want to introduce you to.

This plant is a favorite of mine because it is relatively tall (~ 3-4ft), makes a lot of flowers, attracts a bunch of insects, and tolerates conditions that many other plants don’t like. As is the case for all mountain mints, the flowers of this plant are clustered, and in this species, the flowers are white and bloom in the summer. The plants attract a very large variety of insects and for that reason are one of the recommended plants by the Xerces Society for supporting pollinators in our area. Bees of all sizes, beetles, butterflies, wasps, flies, and hoverflies… nobody can resist this beauty! And to top it all, this plant grows great in full sun and even in relatively dry conditions, which makes it a great one to plant close to roads or in those areas of our green spaces where other more water-needy plants may not do so great.

Hairy Beardtongue – Penstemon hirsutus

I have to say that I have a weakness for Penstemons specifically and plants of the whole family they belong to (the figwort family; Scrophulariaceae) generally. Their complex flowers always get to me, and plants of the genus Penstemon are to me one of those that I can look at and marvel at forever. So, this is one of the first ones I want to grow every time I can… maybe I’ll convince you to plant it too?

The genus Penstemon is almost restricted to North America, where they represent one of the largest groups of native plants on the continent. They are characterized by having tubular flowers, and their coloration varies by species, going from white, to pink, purple, red, and blue. Although there are a few species native to Maryland, and several can be grown, I want to talk a bit about the hairy beardtongue, P. hirsutus (but also check out the foxglove beartongue, P. digitalis!).

The flowers of this species are multicolored, with purple tubes tipped with yellow and white. The flowers are visited by bees (including bumblebees), hummingbirds, and butterflies, and have been described to support the adults of the Baltimore checkerspot, our state insect! The plant itself is not overly tall (~2-3ft) and makes a lot of flowers. They prefer drier conditions and full sun to some shade and will bloom in the late spring/early summer.

Culver’s Root – Veronicastrum virginicum

I feel that plants with small white flowers (like this one) are often kind of forgotten, to the benefit of showier and more colorful flowers. However, Culver’s root is a little gem native to our region that any local interested in supporting pollinators should consider having around.

Belonging to the Plantain family (Plantaginaceae), the genus counts only a couple of species, one of which is the only North American native: Culver’s root (V. virginicum). Like all members of the genus, this species presents its white flowers arranged in long spikes. This species will become taller over the years, reaching 4-5 feet at full maturity. They prefer sunny to shadier spots, where sufficient moisture is present (e.g., wood edges).

The flowers mature sequentially, and because there are so many flowers in their long spikes, a single plant is likely to flower for weeks. Besides its sustained floral display, this plant is super interesting and important for pollinators because it happens to flower at a time when few other plants flower in our region (July-August). Their white flowers attract and provide food for bees, butterflies, wasps, and (hover)flies.

spiky white flowers of culver's root
Once established, Culver’s root can reach 4-5 feet in height, displaying their long spikes of white flowers. Photo: E. Enking (CC)
close up view of culver's root flower spike
A tiny bee collects pollen on Culver’s root (can you spot it?). Note the multitude of flowers present on the long spikes. Photo: A. Espíndola

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, 
extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

September To-do Lists Nudge Gardeners

Winter squash is ready for harvest now.  Photo:  Home & Garden Information Center

I know. I know. You’re tired after a long season of gardening. Especially with all that heat we had. But there are still a few things to tick off your fall to-do list.

Have you planted your garlic yet? Now’s the time. Nestle cloves into the soil through the end of October for harvest next July. Get tips here: Growing Garlic in a Home Garden.

Even if your vegetable garden is looking ragged, keep harvesting. My cucumbers finally gave up the ghost, but I’m still getting enough tomatoes and basil for Caprese salads.

I just harvested butternut squash, too. The rind was finally hard enough not to dent with my fingernail, so they were ready. I’ll cure them for a week in a warmer room, then store them in my cooler basement. Learn more: Growing Winter Squash in a Home Garden.

And yes, I’ve started to remove spent and scruffy vegetable plants, clearing the bed of fallen fruits, leaves, and stems. And no, it’s not just because I’m a neatnik.

Soilborne diseases are the most common cause of vegetable problems. Those plant bits can harbor fungal spores which can reinfect plants year after year. 

So I’m ruthless in removing plant debris. I compost healthy plant parts, but bag and trash anything that has had disease issues.

After cleanup, I add compost. It feeds the soil, adds organic matter, improves drainage, holds nutrients, attracts earthworms, and suppresses disease. What’s not to love?

Buy compost or make your own. Mix leaves, grass clippings, kitchen scraps, and other organic materials into a pile. Stir it now and then, water it when it’s dry, and let it cook down into the best soil food ever. Learn: How to Make Compost at Home.

a gardener working on a compost bin
Master Gardener Gary Stallings turns compost in a teaching garden. Photo:  Shanon Wolf

This year I’ll top off my vegetable beds with an inch or two of compost to improve the soil and act as a winter mulch and weed blocker.  

Yes, weeds grow in winter. Winter annuals such as chickweed, henbit, and speedwell love bare soil, germinating in late summer and fall and returning vigorously in spring.

Don’t let them get a toehold. Cover bare soil with compost, mulch, or a cover crop.

Cover crops are all the rage, a classic farming technique that’s discovered new life in gardening circles. Sown from seed, they block weeds and slow erosion.

Best of all, cover crops feed and improve soil. Their deep roots mine nutrients and their leaves, stems and roots break down to add organic matter when they are turned into the soil in spring.

Many cover crops can be planted in the fall. Which is best for your garden? Find out here: Cover Crops for Gardens.

crimson clover
Crimson clover is an attractive cover crop that improves soil. Photo:  Home & Garden Information Center

After I tend to my vegetable beds, I dig and divide perennials. Most perennials should be divided every 3 years. Just lift a clump, cut it into sections, and transplant and water well.

Resist the urge to cut back your perennials in the fall. They provide crucial overwintering sites for pollinators and food for birds and other wildlife. Only cut back plants that had serious disease or insect issues.

Fall is a time to put a tidy bow on the gardening season, to lay to rest your beds after you squeeze out the last harvests. Feel the change in the air, breathe deeply, and enjoy the delicious ache of a job well done.

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.

  

Goldenrods: The Garden Thyme Podcast

goldenrods episode of The Garden Thyme Podcast

Gold and yellow hues are the undeniable colors of autumn. In this episode of The Garden Thyme Podcast, we discuss one of our favorite yellow-blooming perennial plants – goldenrod. With its pretty yellow flowers, long blooming seasons, and high wildlife value, what is not to love about these fantastic native plants? Mikaela also counts down her top pick of goldenrods for different gardens (~17:10). Her goldenrod bloom chart can be found here.

We also have our: 

  • Native Plant of the Month – Pawpaw (Asimina triloba) (~22:45)
  • Bug of the Month – Goldenrod Bunch Gall Midge  (~33:35)
  • Garden Tips of the Month (~39:15)

If you have any garden-related questions, please email us at UMEGardenPodcast@gmail.com or look us up on Facebook.

For more information about the University of Maryland Extension (UME) and these topics, please check out the UME Home and Garden Information Center.

The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Hosts are Mikaela Boley- Senior Agent Associate (Talbot County) for Horticulture, Rachel Rhodes- Agent Associate for Horticulture (Queen Anne’s County), and Emily Zobel-Senior Agent Associate for Agriculture (Dorchester County).

Theme Song: By Jason Inc 

Beyond Broccoli Part Two: What’s Up with Brassicas?

Welcome back to Beyond Broccoli! Last month I posted about how the genus Brassica is classified and grouped, and where the plants come from in the world. Now let’s talk about what characteristics the brassicas have in common. Here’s some of what they share as a group:

  • An origin in temperate regions. These species originated in Europe and Asia, and most of them prefer to grow in cooler weather.
  • Thousands of years of cultivation and breeding. They’ve been part of humanity’s diet for a long time, and have great cultural significance in many regions.
  • Some physical similarities. I mentioned the cross-shaped (cruciferous) flower in the last post. Brassica seed leaves (cotyledons) have a characteristic heart shape, and seeds are generally small and round. We’ll explore leaf pigments and other commonalities in later posts.
Seed leaves of mustard
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We are still alive! How to protect pollinators in the slow season

Even when they look dry and “dead,” our green spaces are full of life. When we think about plants, for example, we can see that herbaceous perennials seem dry but they are actually just retreating underground, while annuals continue their life cycle by spending the winter as seeds in the ground. The same is true for other organisms that live in our green spaces: squirrels become less active, snakes retreat to sheltered spaces, and insects may overwinter as adults underground or in crevasses or as juveniles in their nests or chrysalises. Among these insects, there is a particular group that we seem to take a lot of effort to protect in season, but that we may then forget about in the fall and winter: our pollinators. In today’s post, I would like to talk about some specific ways that allow us to take care of our green spaces in the fall, all while continuing to support these organisms we worked so hard to support throughout the growing season.

Where are our pollinators in the winter?

As we mentioned in a previous post, pollinators don’t disappear in the winter. Instead, they either migrate to warmer conditions (like monarchs do; check out this website to know where they are now!) or stick around and overwinter right here in protected spaces such as crevasses, underground nests, and within plant stems. If we have been enjoying supporting them throughout the season, it may be a good idea to continue to do so also throughout the winter. Let’s see some ways to do this.

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Fall Colors: The Garden Thyme Podcast

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Fall is almost here, and we are ready. Nothing signals the start of fall like the changing of the leaves. In this episode, we discuss what causes the leaves to change color. It was also really hard to choose, but we picked our top 5 trees with the best fall color.  We also have some suggestions for shrubs, grasses, and flowers that make great additions to the garden in the fall. 

We also have our: 

  • Native Plant of the Month – New England Aster ( ~37:22 )
  • Bug of the Month – Paper wasps (~41:30)
  • Garden Tips of the Month  (~49:15)

The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Hosts are Mikaela Boley- Senior Agent Associate (Talbot County) for Horticulture, Rachel Rhodes- Agent Associate for Horticulture (Queen Anne’s County), and Emily Zobel-Senior Agent Associate for Agriculture (Dorchester County).

Theme Song: By Jason Inc