Sweating Bareroot Trees
Which trees need sweating?
Of the trees that we sell, typically bareroot almond, peach and nectarine trees are the ones that sometimes need to be sweated.
Why do some trees need to be sweated?
During the winter, bareroot trees and shrubs are stored in coolers which are kept at (or just above) freezing and at a high humidity level. For some reason, some kinds of plants have a hard time going directly from this climate controlled environment into the outdoors and still thrive. They just sort of stay in a state of deep sleep and either bud super late in the summer, or never wake up and eventually die. It's not entirely understood why certain plants tend to do this, but thankfully a generations-old tree nursery trick works wonders to gently wake most of those kinds of trees up.
When do I sweat my trees?
Sweat them when you are ready to plant. It may take a few days or up to a month (depending on the environment), but once you see green buds on your trees you need to get your trees into the ground right away. If you live in an area that is a little colder and still getting pretty hard frosts it would be better to heel your trees into the ground for a week or so and wait on sweating. Then, when you are only getting light frosts, go ahead and start sweating your trees.
Ok, so how do I sweat trees?
First of all you want to soak the roots of your trees in water for 1-2 hours. After that you have 2 options on how to proceed -
1st option:
You can pot up the trees and place them in a warm, humid greenhouse. Once you see green buds you can plant them outdoors as usual.
2nd option:
This one is a little more involved but still not complicated or difficult by any means.
For best results you should try to find a place to put the trees that can be kept at around 45 - 70°F such as in a hoop house, barn or garage. If the temps aren't warm enough naturally you should add some supplemental heat. First lay down a large tarp or sheet of plastic. Place a thick layer of wet (but not soaked) packing material such as straw or woodchips on the plastic. Lay the trees on the wet material, then completely cover the roots with more packing material. Finally, completely cover and seal in the plants – tops and all – with the tarp or sheet of plastic and tuck it under well so that it is held tight to the ground. It is important to make sure the plastic is held down well on all sides in order to keep down air circulation and allow the air inside to get nice and humid. Check on the trees daily to every-other day and as soon as you see green buds they are ready to plant outdoors.
If you don't have a building you can put your trees in, it is possible to sweat them outdoors and with no supplemental heat. You just need to be very careful that they don't freeze and that they don't get overly hot either. I have done this by doing the same process as above, but locating the trees in a sunny spot. I covered the plants over completely (including the tops) with woodchips or straw and used a white tarp to seal them in. It is very important that the tarp is white or very light colored in order to deflect a lot of heat and that this is only done when the temperatures outdoors are very mild. Using black or clear plastic in the sun would cook and kill your trees even if the outdoor temperatures are very low. If the daytime outdoor temperatures are more than 60 degrees it would be better to locate the whole works in a shady spot that does not receive direct sunlight.
How will I know when the trees are done sweating?
You are looking for obviously swollen green and breaking buds. This could take between 4 days to 2 weeks or sometimes even a month. Preferably, you do not want to wait until you can see recognizable green leaves starting to push out of the buds. Waiting this long will cause the trees to suffer more transplant shock. Conversely, you do not want to pull them out when the buds are just barely green and not very obvious. If you don't wait long enough to make sure the plants are thoroughly waking up the dormancy will likely not be completely broken and the plants may sink back into sleep again and fail to leaf out. If this happens you can dig up them and try sweating them again, but the likelihood of them coming out of dormancy on the second try is lower than the first.
Of the trees that we sell, typically bareroot almond, peach and nectarine trees are the ones that sometimes need to be sweated.
Why do some trees need to be sweated?
During the winter, bareroot trees and shrubs are stored in coolers which are kept at (or just above) freezing and at a high humidity level. For some reason, some kinds of plants have a hard time going directly from this climate controlled environment into the outdoors and still thrive. They just sort of stay in a state of deep sleep and either bud super late in the summer, or never wake up and eventually die. It's not entirely understood why certain plants tend to do this, but thankfully a generations-old tree nursery trick works wonders to gently wake most of those kinds of trees up.
When do I sweat my trees?
Sweat them when you are ready to plant. It may take a few days or up to a month (depending on the environment), but once you see green buds on your trees you need to get your trees into the ground right away. If you live in an area that is a little colder and still getting pretty hard frosts it would be better to heel your trees into the ground for a week or so and wait on sweating. Then, when you are only getting light frosts, go ahead and start sweating your trees.
Ok, so how do I sweat trees?
First of all you want to soak the roots of your trees in water for 1-2 hours. After that you have 2 options on how to proceed -
1st option:
You can pot up the trees and place them in a warm, humid greenhouse. Once you see green buds you can plant them outdoors as usual.
2nd option:
This one is a little more involved but still not complicated or difficult by any means.
For best results you should try to find a place to put the trees that can be kept at around 45 - 70°F such as in a hoop house, barn or garage. If the temps aren't warm enough naturally you should add some supplemental heat. First lay down a large tarp or sheet of plastic. Place a thick layer of wet (but not soaked) packing material such as straw or woodchips on the plastic. Lay the trees on the wet material, then completely cover the roots with more packing material. Finally, completely cover and seal in the plants – tops and all – with the tarp or sheet of plastic and tuck it under well so that it is held tight to the ground. It is important to make sure the plastic is held down well on all sides in order to keep down air circulation and allow the air inside to get nice and humid. Check on the trees daily to every-other day and as soon as you see green buds they are ready to plant outdoors.
If you don't have a building you can put your trees in, it is possible to sweat them outdoors and with no supplemental heat. You just need to be very careful that they don't freeze and that they don't get overly hot either. I have done this by doing the same process as above, but locating the trees in a sunny spot. I covered the plants over completely (including the tops) with woodchips or straw and used a white tarp to seal them in. It is very important that the tarp is white or very light colored in order to deflect a lot of heat and that this is only done when the temperatures outdoors are very mild. Using black or clear plastic in the sun would cook and kill your trees even if the outdoor temperatures are very low. If the daytime outdoor temperatures are more than 60 degrees it would be better to locate the whole works in a shady spot that does not receive direct sunlight.
How will I know when the trees are done sweating?
You are looking for obviously swollen green and breaking buds. This could take between 4 days to 2 weeks or sometimes even a month. Preferably, you do not want to wait until you can see recognizable green leaves starting to push out of the buds. Waiting this long will cause the trees to suffer more transplant shock. Conversely, you do not want to pull them out when the buds are just barely green and not very obvious. If you don't wait long enough to make sure the plants are thoroughly waking up the dormancy will likely not be completely broken and the plants may sink back into sleep again and fail to leaf out. If this happens you can dig up them and try sweating them again, but the likelihood of them coming out of dormancy on the second try is lower than the first.