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Herbs for your garden tomato's health!

Last season's haul of Black Krim tomatoes. The ones the grasshoppers let us have. It was a bad year.

Look through any seed catalog and it's clear what one of the most popular garden plants is - Tomatoes!

Slicers, high tunnel, small fruited, determinate, weird colored and shaped specialty, indeterminate, heirloom, paste, artisan, grape, cherry - 12 solid pages with 3 columns per page of different tomatoes in my Johnny's catalog! Poor turnips have the one left hand column of one page with 3 different kinds of seeds.

It's clear what we love!

But so do the insects we share our garden with.

Tomatoes have many insect pests:

  • Tomato hornworm: large green caterpillar with horn on the hind end found amongst the leaves - the largest and most destructive pest, plant is stripped of leaves, pelts of frass (insect poop) scattered around

  • Aphids: leaves are covered with sticky excrement called honeydew which is shiny - may cause yellowing of leaves but otherwise don't do a ton of damage

  • Flea beetles: tiny bugs that hop away when disturbed - they chew tiny holes in leaves that can increase the susceptibility to serious diseases

  • Whitefly: small winged insects visible on the underside of leaves - cause yellowing and curling of leaves, whitefly drink the sap which weakens the plant, the honeydew they secrete can cause black mold, a fungal infection

  • Stinkbugs: strong fliers shield-shaped bug in brown or green color, they are pretty easy to see - both nymphs and adult stinkbugs with feed on tomatoes at all stages, sharp mouth parts pierce the skin to suck out the juices which leaves a hard white callous under the skin, fruits are often misshapen or shriveled

Most of these pests navigate to the plant by scent. For you tomato growers out there, you know tomatoes have a strong and distinctive scent.

Planting strong smelling herbs in and around your tomato plants can help "Confuse-A-Bug" and lessen the damage they cause.

The herbs I plant every year to deter pests from my garden are Dill, Basil, and Marigold, not just for tomatoes but also for the cabbage family as well.

Baby dill taking up role of Protector of Cabbage

Dill has a delicious scent and grows very quickly from seed. I just buy the seed by the ounce from the local health food store and spread it around. The first stage is the frond, this is where dillweed comes from! It's a lovely fluffy little puff of a thing which quickly sprouts up and puts on the flower that turns into the seedhead. In the picture below, you can see the third job dill does, it work to block the airspace as the insects try to land on the tomatoes. This is actually a really important job, if an insect tries but doesn't succeed on landing on the target plant an few times, it gets discouraged and moves on. It's good to plant a handful of dill seeds about every 4 weeks to keep a steady supply of dillweed and blooming flowers.

Dill seed head after harvest amongst the tomatoes

Basil is the best. Since I discovered the friendship between basil and tomatoes in the garden, I haven't had a single hornworm. I've tried all different kinds of basil and different timings and I really don't have a solid opinion on if it's better to direct seed or put out a seedling.

I do start my tomatoes inside, for sure. I just started 5 plants of Black Krim and 5 plants of Sungold, my two favorites on 3/28. I'll pot them up in about two weeks and start hardening them off the end of April.

This year, I direct seeded Sweet Basil when I set the tomato starts out. I remember, the seed was a few years old so I seeded in thickly. The germination rate was still very good, so I had plenty to transplant to other parts of my garden.

This year I bought white petunias to plant in with the starts of Sweet Basil in with the tomatoes. It made such a lovely planter.

What I've observed is that basil grows so quickly that it really doesn't matter. Just make sure you plant it all around to deter the pests.

Holy Basil surrounding a tomato plant

Marigolds have multiple pest deterrent skills as well as being a lovely pop of color and a good natural dye. I confess I rarely start these early. They are inexpensive at the garden center and once you have a plant or two, they are vigorous self-seeders.

Old fashioned marigold deterring white fly from healthy greens

Besides being an eye magnet, they are great at repelling aphids and whitefly and might help keep deer and squirrels. My experience with intercropping my cabbage family food crops like cabbage, broccoli raab, and kohlrabi is that marigolds repel the dreaded white butterfly, the cabbage moth who's caterpillars do such damage.

But remember this: you share your garden with your eco-system. The insects aren't attacking you, they are doing what they are supposed to do. The damage they do to your garden can be mitigated naturally with herbs and flowers but your garden will suffer some damage. That is okay. Learn lessons and plan for next year. The time when people can casually spread environmental poisons around for the sake of a perfect leaf or fruit is over. Learn to live where you are, to bloom, and thrive.

Tomato with herb friends dill, marigold, and lettuce-leaf basil. The damage from flea beetles is clearly present, but the plant is healthy.


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