The Root of the Problem
Transplant Shock happens when plants are moved. Unlike humans, plants were not designed to be shuffled around. In nature, once a plant is rooted, that is where it stays. However, we are always waiting to change and design our environment and that means moving plants; either planting new annuals every year or moving, cutting, and thinning existing plants to more aesthetically pleasing areas. So, transplant shock happens when you move plants, but why?
The answer is all in the roots. We tend to talk about roots as if they were one ubiquitous mass. They are, in reality, not a mass but a system with individual parts serving particular functions. The tap root is one or two long, thick roots that generally go straight down, deep into the soil. Think of this root as the “trunk” of your plant. This root serves to access deep reserves of water, to add structural integrity, and to provide a wedge which breaks up the soil and allows for development of the second set of roots. This second set is somewhat smaller and grow out laterally from the main tap root. If the tap root is the “trunk”, these are the limbs and like limbs they stretch out, cross each other, and provide bulk. The main function of these roots is to provide stability, serve as an anchor to the plant to keep it from moving, and to hold the soil so that the plant can get the water and nutrients it needs from its environment. They also serve as host for the most important roots. The third set of roots is the hair-like feeder roots. These roots are very small, even on the biggest plants. They are thin, wiry, and about the size of a human hair. The ends, or growing points, are the only place where the plant can actually take up nutrients and the majority of water. Without getting too deep into the science, this is where the microbes and beneficial bacteria thrive and do their job of converting minerals into nutrients.
The problem with these feeder roots is even though they are vital to the plant, they are also the most susceptible to damage. Some research shows that exposure to the air for even 3-4 minutes is enough to cause them to dry out and die. They are also very easy to break. So, when you transplant the plants, even if you are careful, it is very easy to disturb this section of the root system and when you do, it takes the plant time to replace them. Until then, the plant is getting very little nutrition or water. The plant enters survival mode, any flower is jettisoned as it fights to allocate stored resources for survival rather than reproduce. As more resources are required to re-grow these vital roots, (and because it is getting no nutrition) it wilts. And this reaction is what is known as transplant shock.
So what can you do? Here are a few tips:
1) Be as gentle as possible. Handle the root ball of the transplants as carefully as possible. But know this. Even though you are careful, the feeder roots are so delicate they are going to break; it’s inevitable.
2) Prepare the new home. Even if you are planting into the ground, you will want to provide a new home that is delicate. Heavy clay soils are generally compacted and hard for the tiny roots to penetrate so mix some of the host soil with sand or soilless media and fill the hole loosely BEFORE transplanting. Then remove just enough of the soil to make room for the new plant.
3) Make sure the transplant is not root bound. There should be a good amount of roots at the outer edges but they should not be circling around the root zone in a solid mass of white. If they are, they will need a haircut, either by actually cutting and freeing some of the roots or by pulling them away to thin them out. This will kill of some of the feeder roots, but will cause fewer problems in the long term. You should introduce the plant to its new home as quickly as possible. I usually root-dip my plants for 10 minutes or so in a weak solution of Monty’s 4-15-12 or 2-15-15 (1 ounce per gallon of water) prior to placing them in the new environment. This loosens up their native soil and gives them a quick shot of energy. Then once all the plants are in, I water them in with any remaining solution. The picture to the right is lettuce and spinach two days after transplanting. Notice no signs of shock or wilt. You should place the plant its new environment just deep enough so that the stem and root ball is below ground level. Once the plant is in place back fill with the soilless/host soil mix. Be carefull not to press the soil around the plant as this can lead to problems with compaction.
4) Feed the plant. Some experts advise putting a bit of fertilizer in the bottom of the new home prior to transplanting. I have done it both ways and have not noticed much difference either way. USE A LOW SALT, LOW NITROGEN fertilizer. Nitrogen can burn even healthy plant material, much less tender feeder roots. Plus, nitrogen is the nutrient responsible for growth. There will be a time for that, but now it is too early. One of the biggest problems I see with zealous homeowners is giving the plant too much nitrogen too quickly. This is especially true for perennials and larger transplants like trees and shrubs. For these, I recommend very little nitrogen at all for the first full season. Here’s why. Nitrogen generates growth. The mere presence of the nutrient tells the plant to get bigger, taller, and put on more leaves. If you do that, and do not have an underlying root system to support this vigorous growth a few things can happen: One, the plant will become top heavy and a strong wind will uproot the plant because there are not enough anchors holding it place. Two, and this is the biggest problem. You know that droughts are going to happen. When they do, the plant needs a good root system to access available sub-soil moisture reserves. If, by applying nitrogen, you have spurred top-growth you have increased the burden on the plant by giving it more leaves, stems, and flowers to maintain and by not giving it the root system that it needs to provide the water and nutrients it is starving for. Instead of nitrogen, look for a fertilizer that is relatively higher in potassium and phosphorous (the second two numbers on the label). These are the nutrients that a plant uses to develop good root systems and the ones you need to ensure successful transplants.
By using a product like Monty’s 2-15-15 or 4-15-12 you can give the plant what it needs, and according to gardeners across the country, as well as my own experience, virtually eliminate transplant shock. Get more details on transplanting in our how-to guides on our website. While this is still true for annuals, it is not as critical, cause let’s face it, you will be throwing them away in 6 months anyway. Give them a week or two to settle in, then you can start using a higher nitrogen fertilizer. The low-salt issue is still a concern so I recommend using Monty’s 8-16-8. It’s high in nitrogen, but it has one of the lowest salt indexes on the market.
5) Water. Believe it or not, most homeowners are so afraid of under-watering their new plants, that they go too far and over water them. Over-watering is just as bad. It depletes oxygen form the soil, collapses pore space, compacts the soil, and creates an environment ideal for developing anaerobic bacteria (the bad ones) which leads to rot, disease, and can increase the likelihood of insect problems. If you are watering your plants keep them evenly moist so that they have to grow their roots both out and down. this will give you a better anchor and will get feeder roots out of the topsoil. If the roots stay in the upper reaches of the soil profile you will end up fighting drought conditions throughout the life of the plant as this layer of soil is the first to dry out in the hot dry days of summer. To accomplish this, stick your finger about an inch deep into the soil (up to your first knuckle) at the edge of the drip line. If the soil does not feel noticeably damp at your fingertip, it is time to water.
By following these few simple guidelines and by incorporating Monty’s Fertilitly Products you can get your plants off to the best start possible and virtually eliminate transplant shock.
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