A consistent maintenance program keeps tomatoes growing strong all season
Giving tomato plants the proper attention at planting time is the most important step you can take to ensuring a satisfying harvest. However, even with the best care initially, keeping your tomatoes growing strong will require some mid-season care as they head toward harvest time.
Controlling Disease
Once the plants start to flower and form new tomatoes, keep an eye out for leaf spot or leaf curl on the plant. Another sign of trouble is leaf drop or yellowing leaves. Unfortunately, many diseases common to tomatoes look similar. Some are preventable, some are treatable, and yet others are neither, such as a virus.
The best preventative measures for disease on tomato plants is to be sure to have a 2-4 inch layer of mulch around the base of each plant. This will help a great deal in preventing soil-borne disease from splashing up onto the foliage from irrigation or rainwater. Water plants with soaker hoses, or at the very least water at the base of the plant. If you must water from above, do it early in the day so the foliage has plenty of time to dry out. Foliage that is wet for too long can promote disease. Don’t over fertilize but keep a good supply of compost around the plant. It is a great source of nutrition, and it contains disease-fighting properties.
Once disease is present, it is very difficult to reverse. However, you can in many cases prevent it from happening. Before any sign of disease on your tomato plant, start spraying each plant with a combination of bactericide and fungicide. Combine a copper base solution for the bacteria and a fungicide such as Daconil 2787 into a pump sprayer. Follow the directions on the labels for proper mixing instructions. About every week, apply this solution to the pant foliage and along the stem. According to one well-respected university plant pathologist I know, 90% of the preventable disease problems occurring in home vegetable gardens can be avoided by using this method.
However, even with a consistent maintenance program, which includes watering only at soil level, providing good air circulation and spraying routinely with a bactericide/fungicide, environmental conditions may still promote disease. In these cases, remove diseased foliage from the plant at the first sign of problems. This will likely occur on the lowest part of the plant initially.
Tomato Pests
There are a number of pests that attack tomato plants. One of the most common is the tomato hornworm. This hard to see but intimidating creature can do a lot of damage to a plant in the course of 24 hours. You know you have this pest when you find much of the foliage eaten within a short period. Another sign of the hornworms’ presence is the droppings they produce. They usually appear at the base of the plant and look like small black soccer balls.
Control of the hornworm is simple. Once you locate this well camouflaged creature, handpick them off and toss them out of the garden where a bird is sure to find him. Another method to control the population is to use Bt (Bacillus thuringiensis). You can find this in a canister at most nurseries and garden centers. A very favorable aspect to this product is that it is selective; specific only to the hornworm. It is a biological control that won’t harm beneficial insects, pets or people. Apply a dusting of this powder to your plants once you notice a problem and reapply if rain washes it off.
Additional Care
To promote faster growth and concentrate the plant’s energy into the main branches, snap or cut out the small suckers that grow from the crotch of many branches and the main stalk.
As tomato plants grow, they will need support. Make sure to provide staking or support to keep the plant from falling over and possibly breaking. Staking also provides air circulation and penetration of sunlight. A better harvest will more likely be the result. If you find that the plant is growing too tall to manage, you can cut the top off. Be sure to make a clean cut, just above a side branch.
The key is to stay ahead of any problems by maintaining a healthy garden as described above and inspecting it often. By employing some mid season care you can keep your tomatoes growing strong and greatly improve the chances of experiencing your best harvest yet.
About Joe Lamp'l
Joe Lamp'l is the Host and Executive Producer of the award winning PBS television series Growing A Greener World. Off camera, Joe dedicates his time to promoting sustainability through his popular books, blog, podcast series, and nationally syndicated newspaper columns. Follow Joe on Twitter
I loved your show FRESH FROM THE GARGEN you did a lot more teaching then than now .How not only to grow different things but how to harvest and different ways to store them. I wished I had recorded many of the shows but I didn’t and don’t remember some of the things that would be helpful now. On one show you covered very detailed the different problems with the tomato plant leaves and how to treat them. So my question is would all the rain we have been getting in Kentucky lately cause yellow leaves with back spots. I put down newspaper and wheat straw around my plants (that I learned on one of your Fresh from the Garden shows)when I planted them.
Hi Gilbert and nice to hear from a fan of FFTG! I loved that show as well and have plans to incorporate a way to do more teaching on growing techniques soon. It’s just that my current show is very different. As for your issue with all the rain and the impact it’s having on your plants–while the mulch is really important to cut down on certain soil-borne diseases, it doesn’t help with all the wet weather.
I’m dealing with the same issues here in Atlanta. After heavy rains for a week over the 4th of July, my plants have plenty of bacterial and septoria leaf spot, as well as early blight. As an organic gardener, the best defense is a very proactive, daily approach of cutting out any signs of disease. That requires a time investment but it’s worth it in cutting down on the spread. You could also use copper-based fungicide spray to keep the disease somewhat in check. But again, my daily regime is to get out with a sharp pair of snips or scissors so I can reach into the plant to cut out leaves and branches all the way to the main trunk whenever I can. The more of the disease I can remove from the plant, the better chance there is to keep it from spreading, or at least slow it down.
Good luck Gilbert.
why is rain water on the leaves ok and not watering leaves myself
It’s not that it’s “ok” but there’s nothing you can do about it. The key is to minimize the amount of water on the leaves and controlling what you can.
Always grow cleome near your tomatoes the bees love them,thus guaranteed pollination of your tomatoes!
My tomatoes look great this year, as far as preventing diseases on tomatoes , you forgot to mention, don’t plant you tomatoes in the same spot year after year. And buy tomato seed with the most disease resistance. A good Hy.
When I plant my tomatoes, I use the “tomato” cages and weave in 2 taller stakes on opposite sides of each cage at time of planting. When the plants get higher than cage, I have stakes available to tie tall branches to. This also adds support to the cages if and when we have major storms.
I really enjoy your newsletter.
I don’t usually havea fall garden but am planting turnip greens and spinach. Are there any compatible flowers to help ward off pests, as in tomatoes and marigolds?
Donna, I don’t really find pests to be enough of a problem in a fall garden to need to address it. I know you are only asking about companion planting but I don’t have any specific suggestions for fall/cool season crops. But if you want to look into this more, there is a book out there called Carrots Love Tomatoes by Louise Riotte. It would be the book I would get if I were you. I have it and it does address cool season crops, including turnips and spinach. Try finding it in the library though if you don’t want to buy. The info may not be as much as you’re looking for.
Have you tried Gardeners.com
Have you tried Garderers.com??
We love gardeners.com. An employee-owned business run by avid gardeners. Nothing wrong with that. Plus they have lots of great stuff!
I grown tomatoes and pepper and cucumbers each year in my large hoop house in North Idaho 80 miles from Canada. I grown everything in large plastic pins, one plant per pin. My question is, if I alternate planting the tomatoes in the pepper bin with the addition of some new compost and potting soil is that enough rotating? I always pull the plastic off my frames during the winter and leave the bins outside. I raise the sides, front and back during the day and lower them out nite to keep the deer out and cooler temps as September rolls around.
thanks
Nathlie, since tomatoes and peppers are in the same family, a sound crop rotation model would suggest you not alternate between the two. It is good that you are adding more soil and compost, but what’s in the existing soil is the issue. So, best if you can rotate your tomatoes and peppers with something other than eggplant and potato (also in the same family as tomatoes and peppers). But I like the idea of how you are growing in large bins.
One more bit of food for thought. You may find that you don’t encounter the problems commonly associated with the reasons people find the need to rotate their crops. In a home garden, and especially in raised bins or containers, you eliminate some of the risks. Keeping your soil replenished with compost and fertilizer will replace the nutrients that will be needed for the next crop. The other issue is the over-wintering pests, IF they find their way into your soil. That would be harder to deal with.
But since you are a home gardener it sounds like, not dependent on raising crops for a living, crop rotation may not be as critical for you as a commercial farmer.
Good luck.
Do you have any other non-chemical solutions for mid-season tomato care?
Good question Lynn. I don’t use anything at all to deal with pests on tomato plants except occasional Bt (Bacillus thuringiensis). It’s a safe bacteria that comes in a liquid and powder. It’s used on tomatoes primarily to kill tomato hornworms. I just pick mine off by hand.
For disease, mulch and removal of infected leaves and stems is my primary method of disease control. However, if you want an organic approach to disease control, you could spray your plants with a bordeaux mix. This following excerpt is taken directly from Wikipedia:
“(also called Bordo Mix) is a mixture of copper(II) sulfate (CuSO4) and slaked lime (Ca(OH)2) used as a fungicide. It is used in vineyards, fruit-farms and gardens to prevent infestations of downy mildew, powdery mildew and other fungi. It is sprayed on plants as a preventative; its mode of action is ineffective after a fungus has become established. It was invented in the Bordeaux region of France in the late 19th century. If it is applied in large quantities annually for many years, the copper in the mixture eventually becomes a pollutant.”
It’s me again. The copper can build up to toxic levels for your plants if you continue to use. But it’s the best option I know of for treating diseases on your plants before they appear in a non-synthetic chemical way.
Hi Joe,
Blessings upon you for giving your horticultural skills to the public. Great show!
I am frustrated with the tomato cages I find in the stores and nurseries. My plants easily reach 5 or 6 feet high. Can you recommend a hardy tomato cage for this size of plant?
Mark Goodsmith
Robins, Iowa
I use peoples discarded 2 x 4’s….or I purchase pressure treated 2 x 2’s from Home Depot/Lowes….6′, 8′, 10′ long…I rip them to 1 x 1’s…I then tie three each of the poles together to make a teepee….each pole is horizontally tied with 18″ 1 x 1’s at the bottom, leaving 14 ” available to sink into the garden…again using 1″ x 1″ at 12″ long at 24″ from the first horizontal tie..I continue up till I am comfortable with the
teepee being strong…
My tomatoe plants are 6′-12′ long….they produce awesome fruit..cherokee and striped german heirlooms..
You can also use plastic electric pipe at small diameters….very strong and doesn’t break down…
As the plant grows I tie off the stems with twine for vertical support…the 14″at the bottom gives me ample room to place the fertilzer and mulch….
I have been very happy with this structure…when the season is finished, I dismantle and store away the next year to start again….VERY STRONG….GOOD LCK
Excellent information here William. Thanks for sharing. I’m convinced the only way I”m going to get the ultimate tomato support is by making them myself. Good for you!
I would think that pruning bottom leaves and mulching should have been done shortly after planting.
Respectfully,
Don
Right Don. I remove bottom leaves and mulch early in the process. But removing the lower growing leaves is something I continue to do throughout the season as diseases that form on the lowest branches make their way higher into the plant. It’s an ongoing process of trying to stay ahead of problems. Just as adding mulch if you haven’t done so earlier. Mulch is best added early but always better late than never. Thanks for your comment.
I’m so happy to have found Growing a Greener World! It might be the only newsletter I don’t immediately delete from my inbox. Thank you for the quality, helpful information. It always makes me feel excited to go out to the garden and get my hands dirty.
Bless you McKenzie! That is saying a lot and we so appreciate it. Thanks for taking the time to let us know. You made my day!
Hi,
I was really looking for guidance as to when I thin out the bottom leaves of my Ailsa Craig tomatoe plant which is outdoors. Looking a bit thick at the moment but quite healthy – fingers crossed.
Thanks -barbara
Removing the bottom branches from your tomato plant won’t hurt anything. In fact, it may help help keep diseases from splashing up onto your plant from the soil. Since you have a lot of thick growth above, go ahead and thin some of the bottom growth now.