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.

Be Proactive to Prevent Vegetable Diseases

When it comes to vegetable diseases, an ounce of prevention is worth a pound of cure. Many diseases can be stopped before they start with smart garden practices.

Spring rains cause spots, dots, and fuzzy blots to pop up in everyone’s vegetable patch. That’s fungi having fun. But whether our weather is wet or dry, fungi, bacteria and viruses stand ready to harm plants. 

So, how do you keep them at bay? Be informed and watchful. Look at your plants often to spot small problems before they get big and use the following tips to prevent disease problems.

If you have repeat offenders – diseases that show up year after year – look for disease-resistant varieties. For example, there are varieties of tomatoes labeled as resistant to both verticillium and fusarium wilt. 

Early blight is a common disease of tomatoes. Photo:  J. Traunfeld, UME

Some plants are available in certified, disease-free starts. Choose potato tubers, garlic bulbs, and asparagus and rhubarb crowns that are certified and disease-free. 

Vegetables hate soggy soil. If your garden area is wet, consider creating a raised bed to improve drainage. Or, grow in containers or move the garden to an area that drains well.

You’ve heard me preach the gospel of compost time and again. But did you know that compost actually discourages some plant diseases? Garden smart by adding compost every year. 

Help prevent disease by spacing your plants properly to encourage good air circulation. Plant labels often give spacing tips as do garden books and websites.

Warm, humid weather invites powdery mildew on squash. 
Photo: UME Home & Garden Information Center

Rain can spread soil-borne diseases, splashing infected soil up on plants’ leaves. So keep your soil covered with an organic mulch such as untreated grass clippings or newspaper covered with straw.

Fungi love wet leaves, so water wisely. Water at the base of the plant using soaker hoses or drip irrigation. And water in the morning, not the evening, so leaves dry before nightfall. 

Practice tough love. Remove infected leaves or pull entire plants if they become badly infected. It’s better to lose one bad plant than the whole row. Don’t compost sick plants: bag and trash them.

Overripe vegetables invite disease organisms. So, harvest your vegetables before they get mushy. 

A thorough cleaning of your vegetable bed at the end of the season is crucial since many diseases can overwinter in the soil. Again, if anything had a serious disease issue, bag and trash it.

If you spot a problem, e-mail your local Extension horticulturist a photo or bring them a sample to identify. Here’s a list of our county offices. We can usually get back to you in a day or two with advice.

For other growing tips and diagnostic help, visit our Home & Garden Information Center website. It has photos, management tools, and a wealth of resources. There’s even an Ask Extension link to submit gardening questions to certified horticulturists.

Enjoy your vegetable garden this year. A few seeds and transplants, some rain, sun, and a watchful eye will have you enjoying fresh, healthy homegrown food all season long.

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.