June 11, 2016

1 - Transplanting ornamental small trees from pots after they have grown there for a long time can be challenging.

Yard and Garden June 11, 2016


A lady that has some Japanese maple trees that she has had in pots outside for 12 years! She says they are doing great but she is wondering if she should plant them in the ground.

- Jessica S.

Silver City, NM


I like the old saying "If it ain't broke, don't fix it!" If the trees are doing well in the pots, changing things now may cause problems. Transplant shock may set in, circling roots will still be circling. If circling roots are cut, the top may be damaged after 12 years of being confined. Transplanting now will be stressful in any case, even if we have a good monsoon season with good rains, the Japanese maple tree will be stressed by the heat. Transplanting during the dormant season would be less stressful, but never the less, there may be transplant shock and the circling root problem will still exist.

Remaining in the pots may shorten their lives, but if they are doing well now, they may survive for several more years. Transplanting is more likely to have negative consequences.

Why does she want to move them to the ground? Does she wants them to have the capacity to grow larger, although Japanese maple trees are not large trees anyway? Does she want them to have a chance to live longer, or to add beauty to a different part of her landscape? It would be better to start with new, younger trees without circling roots in the pot, or at least younger trees that can more readily tolerate the pruning of circling roots.

If her trees produce the winged maple seeds, she can start her own seedlings from those seeds in the location where she wants them to grow. In this way the roots will never be disrupted by transplanting and within a few years they should produce nice Japanese maple trees. If she would like to try this these seeds should be harvested when mature and treated to "cold moist storage" to simulate winter conditions since this is a temperate zone tree and needs winter conditions for seed germination and for growth.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.


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