Tomato Transplant Shock: How To Avoid

Left hand holding tomato seedling and the right hand digging a hole using the trowel.

Transplant shock is a common problem for tomato growers. It usually happens when you replant delicate seedlings into a new environment. The process causes them stress due to unfamiliar temperature, wind movement, and too much brightness.

Transplanting tomatoes from one place to another is traumatic and can cause root damage. Root damage is the primary cause of most transplant shock.

Most plants can adapt to the change of environment, but you should make it gradual and in a progressive way.

Transplant shock does not only happen due to mishandling tomato seedlings during transplanting. A sudden change in environmental conditions also causes transplant shock.

Aside from tomato seedlings, most young plants suffer transplant shock when transplanting, especially newly rooted cuttings.

It happens if you move them from a high humidity environment with low-intensity lighting such as moving from indoors to outdoors on a sunny day.

How To Avoid Tomato Transplant Shock

Tomato seedling replanted in a black plastic container.

The possibility of transplant shock lessens if you handle the seedlings correctly during the transplant process.

Complete elimination of stress during the transplant process may not be guaranteed. However, transplanting the right way will help reduce the stress as much as possible. Here are some useful and practical tips on how to do this.

1) Prepare Materials Beforehand

When considering moving a plant from its pot, make sure to prepare the necessary materials like the potting mix beforehand.

When you opt to use soilless growing media, preload the medium with essential nutrients before transplanting.

2) Harden Off Your Seedlings

Tomato seedling replanted in a black plastic container.

Allow your seedlings to harden off at least a week before the day of your transplanting schedule.

Making your seedling to get used to the outdoors gradually is what hardening off means.

Plants raised indoors from the beginning are not used to the brightness of the sun, the changing temperatures outdoors, and the blowing winds.

Avoiding bright light in the first few days is one of the most efficient ways to prevent transplant shock.

Moving the plants outside can cause sunburn or frostbite. This is why introducing the seedlings gradually into the outside environment is essential.

  • Allow them to stay in partly shady or in a sheltered area for about an hour on the first day outdoors.
  • On the next day, increase the amount of time by an hour or two when staying outdoors. Slowly expose them to the sun indirectly.
  • Keep increasing their time outdoors each day. Let them adjust to being outside until they can withstand the whole day without showing any signs of wilting.
  • When getting your seedling from a nursery, they need acclimatization too. This depends on the circumstances they were presented while on sale, and how similarly these conditions are in your garden.

3) Fertilize Before Transplanting

Freshly transplanted tomato seedling in a garden bed.
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Transplanting In-Ground
  • Fertilize planting spots beforehand to ensure the plant’s health and prepare them for the coming transplant.
  • If you’re considering transplanting your tomato seedlings in-ground, dig a planting trench or a hole a bit deeper. This will allow plants to develop and establish more roots.
  • Sprinkle dry fertilizer about a quarter cup depending on the size of your planting hole or size of trench. Use a trowel to mix the fertilizer into the soil properly.
Repotting Into a Bigger Pot
Tomato grower transplanting tomato seedling into medium-size, orange, and oval plastic container pot.
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  • Prepare the clean container pot with high-quality potting media. You can also mix your own potting medium.
  • Transplanting tomato seedlings before they become root-bound is a smart idea, particularly when they germinate together in a whole big platter. Separating at such conditions will keep them unharmed.
  • Tomato plants are heavy feeders. However, they need a balance of nitrogen, potassium and phosphorus to encourage healthy root growth.
  • Like transplanted seedlings in the ground, repotted tomatoes need generous feeding to encourage healthy growth.

If possible, give your freshly transplanted seedlings a strengthening drink of liquid fertilizer like seaweeds or mushroom compost tea. Plants absorb liquid nutrients quickly to help manage transplant stress.

4) Transplant Carefully

Tomato seedling newly slips off from the original pot.
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Remove seedlings gently from the pots to avoid damaging the roots when transplanting. Either you will consider replanting them into the ground or repotting into the bigger container pot.

Turning the pot upside down and by supporting the soil with one hand, place the stem between your fingers. This is the easiest way to slip the seedling off from its existing pot without damaging.

5) Avoid Transplanting On A Bright Sunny Day

Tomato grower transplanting tomato seedlings into a garden bed.
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Water the soil of your seedlings 30 minutes before removing from its existing pot. Doing so will nourish the plants beforehand as they tend to close their stomata during the transplant. Closing of the plant’s stomata happens when the guard cells lose water and become weak.

A cloudy day with a moderate wind is the best time for transplanting.

If the weather keeps on shifting after preparing the necessary materials, be prepared to cover the plants immediately. Protect the plants from sunburn, extreme wind movement, and too cold of temperatures.

Remember that an hour of extreme wind movements or the remarkably hot sun is enough to cause harm to your seedlings.

6) Keep Tiny Hairs From Getting Damaged

Four tomato germinating seeds with hairy roots.
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When tiny hairs of tomato roots are exposed to bright light, heat and scratches, they can get damaged.

The plants are likely to suffer from transplant shock. These tiny hairs of the roots usually function as the moisture and nutrients absorb from the root ball.

Tomato roots hate being disturbed. When repotting or transplanting into the ground, be careful not to shove, shake, or hit the roots. This can cause commotions and undesirable consequences.

However, if the seedling is root-bound, you need to lightly tease the roots to loosen before planting.

Also, remember to dig the hole wide enough for transplanting. Trying to jam in the plant in a small tiny hole could potentially damage the root hairs.

7) Water Thoroughly

Watering freshly transplanted tomato seedlings in a garden.
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Water freshly transplanted tomato seedlings well as the plants won’t be able to take in water through their leaves for a few days.

Insufficient supply of water after transplanting can increase the possibility of transplant shock.

Watering plants thoroughly can settle the soil around your plant’s roots, filling all the spaces underneath the soil surface.

Usually, it takes several weeks for newly transplanted seedlings to establish new roots and begin drawing nutrients and moisture from the soil.

Until such time, check your plants and water regularly to make sure the roots don’t dry out.

8) Monitor Regularly

Freshly transplanted seedlings are stressed enough from the process of transplanting and do not need extra stress due to bugs and pests.

Check your newly planted plants regularly and be ready to eradicate a few bugs that manage to attack the plants in their current location.

9) Provide an Ideal Environment

Newly transplanted tomato seedlings inside a greenhouse.
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Aside from moving your transplant into their new location, you also have to consider their growing environment.

Providing your plant’s roots with an effortless transition is also one of the crucial phases after transplanting.

This will allow the plants to direct their energy on establishing a firm rooting system. It will help them grow faster rather than struggling to survive.

An environment with too much air movement can contribute stress to the plants. This will force the seedlings to work hard and withstand such an atmosphere more than necessary.

Humidity also plays a significant role in determining how the roots need to work because maintaining ideal humidity can help freshly transplanted tomatoes avoid possible shock.

The warm temperature should be no more than 75°F (24°C) and not lower than 70°F (21°C) to help mitigate the plant in its transition period.

Transplanting Tomatoes Aftercare

Tomatoes are not that hard to grow if you follow the few easy tips we’ve shared above. Of course, you want the best care you can provide to your newly planted tomatoes to allow the plants to grow to their full potential.

To help them reach their potential, here are useful aftercare tips you can follow to grow tomatoes successfully.

1) Mulch Your Tomatoes

Tomato plant with straw mulch among the base.
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Mulching your tomatoes is essential for several reasons. These include:

  • Helping conserve soil moisture.
  • Suppressing annoying weeds that steal nutrients your plants need.
  • Helping warm the soil quicker in the spring. This will allow freshly transplanted tomatoes to grow fast, even in the colder weather.
  • Helping keep the soil from washing away during the heavy rain.
  • Mulching also helps prevent soil-borne diseases like blight.

2) Provide Staking

Providing your tomato plants with stakes or trellises is also necessary, as they are considered vines and need support to keep off the ground, and keep the fruits from possible rot.

Tomatoes left on the ground usually rot before they become ripe. No one wants rotten tomatoes after all.

3) Pruning Suckers Is Required

Hand holding a tomato plant stem with a sucker in the limb.
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Pruning tomato suckers while the plant is young is necessary. This will force the plants to focus their energy on establishing a firm rooting system and encourage healthy growth and long term production.

Suckers are those small branches that form a “Y” in the limb or the main stem. You can snip them off using your thumb and forefinger.

Make sure to snip off the bottom set of limbs of tomato plants that are touching the ground or mulch. These limbs often turn yellow early once the plants start to mature, and usually are the cause of plant disease like blight.

These can affect and limit the potential plant growth and negatively impact quality produce.

Its contact with the soil or mulch is the reason for catching the disease. However, when the plants begin to reach maturity, stop pruning the suckers to avoid possible sunscald.

4) Nip Off Early Blooms

Prevent early blooms by pinching off any blossoms you may find until the plant reaches at least 30-36-inches tall.

Allow tomatoes to establish a solid rooting system before setting fruit. Setting fruit too early can cause low production the entire season.

5) Check Out For Wilting

Wilting a newly transplanted tomato seedling.
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Wilting is usually associated with a lack of hardening off and a lack of water, particularly for newly transplanted tomatoes. Make sure to water the plants thoroughly, especially in the first few weeks after transplanting.

However, tomatoes that suffer from wilting right after transplanting may be caused by how you handle the seedlings during the transplant process.

Damages in the seedling like breaking the branches or stalks can happen in many ways during the transplant, resulting in possible wilting.

Another common reason is when transplanting happens at the wrong time. So take your time and always consider the weather to avoid wilting.

6) Do Not Over-Fertilize

Yes, tomatoes need fertilizer, but giving them too much nitrogen will result in lush foliage but fewer to no fruits. Over-fertilization can also cause damage to the plant’s roots resulting in their untimely death.

Sometimes, it is tempting to add fertilizer to make your plants grow bigger and faster. But tomatoes should only be fertilized three times in their entire growing season. The first time is when they are transplanted, next when they start to bloom, and the last one is when they begin to set fruit.

7) Give Them Compost Tea

Giving your plants a refreshing drink of tea like mushroom compost at least once a week will lessen the chances of pests and diseases. Thus, it will make them healthy, vigorous and fruitful.

Final Thoughts On How To Avoid Tomato Transplant Shock

Although transplanting may seem like an easy process,  it is indeed a painful process when it comes to your seedlings. It is a crucial phase of the plant’s life, and whether or not you will enjoy the productive yield relies on the success of transplanting.

When considering transplanting, remember to give your seedlings a couple of days to adjust before the scheduled day.

Allow them to acclimatize the fluctuating outdoor temperatures, bright sunlight, and strong wind movements.

Gradually introduce them outside about a few hours on the first day, making it a half-day on the following day, then a full day, and finally a full day and night.

As we already know, transplants are sensitive to shifting temperatures. They cannot withstand extreme hot or too cold, particularly frost.

Sometimes, frost occurs late in the season, so it is best to prepare a protective barrier like a row cover. If the temperature forecast drops below 40°F, reschedule the day of the transplanting.

When using a row cover, don’t forget to support a frame to avoid direct contact with the freshly transplanted seedlings. Such an occurrence can damage the plants badly.

Another way to avoid transplant shock is to replant tomato seedlings on a cloudy day. Make sure the air and soil temperatures are cooler when transplanting, so the heat won’t burn your young tender seedlings.

Also, airflow is essential when replanting your tomatoes. When considering replanting in-ground, ensure the right spacing to avoid blight and other fungal diseases.

Watering your newly transplanted tomatoes is essential, but overwatering can cause root rot and fungal diseases. Water seedlings thoroughly after transplanting but allow the soil to dry when hydrating again.

Do the soil finger test to ensure it is dry, and that the plants need water. Try to stick your finger in the soil about two inches deep from the surface, and if you feel it wet, do not water the plants.

Adding mulch and trellises after a few weeks of transplanting is essential to ensure the plants get the ideal temperature and support they need. Mulch prevents weeds from taking nutrients your plant needs aside from helping regulate soil moisture.

Finally, don’t forget to monitor the freshly replanted young plants, particularly their health and growth. It is especially essential in the seedling stage. They are too young to compete with persistent weeds and resist pests like cutworms and flea beetles that love tender plants.

About Benita Abucejo

Hi there! My name is Benita Abucejo. What can I say? I truly love spending my days in the outdoors, specifically in the garden. Gardening has always been a strong passion of mine since I was a little girl. It has brought me so much joy and happiness that it is definitely safe to say that I will be a gardener for life. For a period of time, I was able to work with people who are into home gardening and I found it to be quite beneficial to my physical health, as well as my mental well-being. Here at Seasonal Preferences, I am going to share with you my experience and ideas so that you can fulfill yourself with the same satisfaction and happiness. Of course, if you have ideas, I would love to hear those as well! Being creative in the garden can really be quite fascinating so let's share our experiences and be the best gardeners we can be. With that being said, thank you for dropping by and please leave me a comment on one of my posts if you would like to get in touch!

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