BONNIE’S GARDEN – 4 Ways to Prevent Garden Problems

Are you planting your first vegetable garden this year—or have you gardened in the past but always seem to wind up with one problem or another?

Unfortunately, our commonly grown garden vegetables are prone to certain problems. Tomatoes can get Early Blight, Late Blight, Southern Blight, Gray Leaf Spot, Septoria Leaf Spot, Verticillium Wilt, Anthracnose, Fusarium Wilt, etc. as well as aphids, stink bugs, and tomato hornworms.

Cucumber family members (cukes, squash, melons, pumpkins) can get Wilt, Powdery Mildew, Downy Mildew, Alternaria Leaf Spot, Mosaic, etc. and are particularly prone to squash vine borers and squash bugs.

4 Ways to Prevent Garden Problems

Here are four things you can do to help prevent problems in your garden.

Keep your garden free of weeds and debris

Plants don’t like to compete for nutrients. But even more important, weeds and debris give insects a place to lay eggs and/or hide. And they provide a breeding ground for diseases.

Allow adequate air circulation around your plants

I know—when you have a limited amount of space, you want to cram as much as you can into it. But with our high humidity here in Virginia, we are just asking for trouble. Planting too close together limits air circulation around the foliage and it allows insects and diseases to transmit easily from plant to plant.

Avoid wetting the foliage when watering your garden

We already have high humidity to deal with during summer—and our veggie garden plants don’t like humidity. Why compound the problem by getting water all over the foliage when we water? I’m a big fan of soaker hoses because they put the water right where you need it—on the roots—and not where to don’t need it. If you don’t use a soaker hose, then water with a hose—at the base of the plant where they need it.

Be observant

Get in the habit of checking your garden every day or two. Insect or disease problems are so much easier to deal with if you catch them early. Check the back of the foliage for insects or eggs and treat them immediately. Eggs can be easily removed by using the sticky side of some tape. Simply pat them and, voila! Gone. Insects can be dealt with Neem oil or any good organic pesticide. Remember to spray just before dark to avoid killing bees.

What to Look For

Check for foliage that doesn’t “look right.” Here is a brief description for some of the more common garden problems—for a better diagnosis, check online for a picture of your problem.

Blight (Early or Late)

Circular or irregularly shaped dark spots surrounded by yellow on older leaves first. Stressed plants are most at risk. Do not allow plants to wilt. Water thoroughly without over-watering. Do not fertilize until the first flowers appear. Use a lower nitrogen fertilizer (like Espoma Organic’s Tomato-tone). Blight can be easily transmitted when foliage is wet so avoid handling plants. Pick off the affected foliage and treat the plant with a mild organic fungicide.

Fusarium Wilt

Yellowing and wilting of leaves tend to occur on one side of the plant. In early stages, top growth may wilt in sun and recover in the evening, regardless of whether or not the soil is moist. Planting in a well-draining spot is essential. Remove and destroy infected plants as there is no effective home treatment.


Yellowing and wilting of leaves will occur all over-starting at the bottom. Top growth may wilt in sun, early on, and recover in the evening. Plant tomatoes in well-draining soil only. Remove and destroy infected plants.

Septoria Leaf Spot

Small spots with darker brown margins appear. Heavily infected leaves will turn brown and fall off. Wet foliage and prolonged spells of wet cooler weather can affect. Do not use overhead watering. Remove and destroy infected plants.

Tobacco Mosaic

Yellowish green and dark green patches. New leaves may be “ferny” and distorted in appearance. The infection of a garden plant can be caused by smoking near tomato family members. Do not smoke or handle tobacco products near tomato or related plants. Mosaic can also show up in cucumber family members.

Powdery Mildew

A grayish-white film appears on foliage. Cucumbers and squash are very prone to it. Our high humidity is the culprit. Avoid getting water on the plant foliage. When it first shows up, remove the worst of the affected foliage and apply an organic sulfur-based fungicide—spray very early in the morning or just before dark to avoid sunburn. Keep weeds and debris out of the garden to avoid spores wintering over.

Blossom End Rot

Ever gone to pick that beautiful ripe tomato only to find the bottom is black? That’s a disease called Blossom End Rot. Tomato family members are prone to it. It is caused by calcium deficiency. This is why I use Tomato-tone—it has added calcium. Eggshells crushed and added to the soil will help—in several years once they have composted down.

More Questions?

Here at the Great Big Greenhouse and Nursery, we love plants and we’re here to answer your questions and make recommendations for your specific garden. Stop by today and let us help you make your garden the envy of the neighborhood.

To read more posts from Bonnie, visit our blog

14 thoughts on “BONNIE’S GARDEN – 4 Ways to Prevent Garden Problems”

  1. We have a persimmon tree and the birds/squirrels seem to get to the fruit before they are ripe. Any suggestions to keep them away? Lest year we only could 2 usable persimmons.

    • Lori–there are several things you can try and, unfortunately, it make take several of them together to help. You can suspend aluminum pie pans from several branches in your tree. Their waving around in the wind, as well as their reflectiveness may help startle and repel birds and/or squirrels. Two or three rubber snakes wound around a branch may make them stay away from what they see as a predator. You’d want to move them around occasionally so they don’t get used to them being it one spot. Other predator decoys like fake owls can also work. Making a bird “happy spot” the opposite side of the yard may help–hang bird-feeders, suet cakes and tuck in a bird bath. If all else fails, there is bird netting available.

  2. What type of insecticide you recommend for insects who like to eat the leave on any type of plants ; like ,tomatoes, beans, green peppers .

    • I recommend Captain Jack’s Dead Bug Brew–yeah, funny name but a very effective organic spray. Timing is important–to avoid killing pollinators which are out and about during daylight–I’d spray just before dark–about eight at night. That way most of the bees and butterflies have gone home for the night and this will allow the plant to be dry before the good guys come back out in the morning. Remember, we want to avoid killing pollinators because so many of our veggies need to be pollinated in order to set fruit. Plus, since most “bad guys” are out eating at night, you’ll get more of them, too, by spraying just before dark.

  3. My tomato plants are growing great but the leaves are covered with little Whit flecks which I assume are some kind of bug. Do you know what they are and how do I get rid of them ?

    • Hi Pam, a picture would really help right here or you could put a leaf in a baggy and bring it buy for a positive ID. Do the “flecks” fly off when you disturb the leaf? If so, then they are white fly. Are the “flecks” clustered on the newest leaves? Then they are probably aphids. Captain Jack’s Dead Bug Brew is a very effective organic spray. The important thing is to spray at night–just before dark. That gives the bees and butterflies a chance to go home. If it’s aphids, then even a good sharp mist from the host will knock them off. Doesn’t work for white fly, though. They just fly off.

  4. Thank you. I think they are aphids. Hosing seems to remove them but they do come back. I’ve been planting tomatoes for 15 years and never had them before!

  5. Pam, aphids will come back, but at least they’re easy to remove! Yes, this has been a bad spring for aphids. Probably due to the mild winter.

  6. Thankyou for telling us to not water foliage. I will not do that after today. I have 2 tomato plants started. I plan to put out pepper plants too. I have also planted marigolds so deer won’t eat young shoots. I also remember that you use cayenne powder to keep deer from the new plants.

  7. Hi Jane. Yeah, with our humidity around here, we certainly don’t want to get the leaves wet!

    Marigolds are great companion plants for veggie gardens–so are any herbs–deer don’t like them either. Cayenne peppers are good at keeping deer/rabbits, etc. from nibbling on things. There is a spray called Hot Pepper Wax which also helps.

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