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.

Native Plants Add Beauty and Support Wildlife 

wild bergamot flowers are lavender color
Native wild bergamot (Monarda fistulosa) attracts pollinators from butterflies to hummingbird moths and is both deer and rabbit-proof. Photo: Elmer Verhasselt, Bugwood.org

I love native plants. I garden for beauty and wildlife and nothing supports healthy habitats better than native plants. 

So what are native plants? They are beautiful, resilient plants that naturally occur in an area.

Having evolved over millennia with native wildlife, they naturally support them best. A native white oak supports 557 species of butterflies and moths while a non-native gingko tree supports just five.  

So if you want to support bees, butterflies, and beneficial insects that help control pests, native plants are the way to go. 

They also support larger wildlife such as birds with their seeds, fruit, shelter, and places to raise young. Again, native plants evolved with them, so they naturally provide what they need.  

According to conservationist, author, and entomologist Doug Tallamy who penned the bestsellers “Bringing Nature Home” and “Nature’s Best Hope,” native plants support 29 times more wildlife diversity than non-native plants.  

Well adapted to our soil and climate, native plants are resilient with a capital “R.” They’ve persisted through many hot, dry, wet, and cold years, surviving all previous climate change that has occurred, positioning them well to adapt to future changes. 

Adapting over eons makes you tough. Native plants have fewer pest and disease issues and some have deep roots which make them drought resistant. That means less watering, fewer chemicals, and a healthier landscape. 

Did I mention how beautiful they are? There is a nasty rumor out there that native plants are weedy. Bosh and balderdash.   

Native coral honeysuckle trumpets red/yellow/orange flowers that welcome hummingbirds. Threadleaf coreopsis wafts a riot of petite yellow daisies in a drift of lacy foliage.  

Wild blue indigo sports 4-foot stems of deep blue sweet-pea-like blooms. Cardinal flower flashes brilliant red and is a magnet for hummingbirds and butterflies.  

Bees love to rummage among the pure white blossoms of native foxglove. And goldenrods carousing with purple asters are the very definition of fall beauty.

Don’t get me started on native trees and shrubs. I love ninebark’s white pompoms, the red dangling fruit of chokeberry, the deep maroon flowers of Carolina allspice (native from our South), skinny willow oak leaves, and the giant leaves of pawpaws

red flower of Carolina allspice
Carolina allspice (Calycanthus floridus). Photo: Miri Talabac

How can you find out what native plants might work in your landscape?  

Discover many resources – including recommended native plants for Maryland on our website and on the Maryland Native Plant Society website.

My favorite native plant reference, “Native Plants for Wildlife Habitat and Conservation Landscaping,” has color photos and plant profiles. Download it for free.

Where do you find native plants? Visit your favorite garden center. Native plants are becoming more common. If they’re not there, ask. Nurseries grow and buy based on client interest.  

The Maryland Native Plant Society website also lists native plant sales and nurseries on their website.

Many Master Gardener groups – including ours – hold spring plant sales that include native plants. Contact your county/city coordinator to learn if one is scheduled near you.

I hope I’ve encouraged you to include some native plants in your landscape to add beauty, invite wildlife and support a healthy ecosystem.  

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.