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Happy Re-potting Season in the northern hemi

I just want to wish everyone a Happy Repotting Season in the northern hemi.

Or as I think of it, the Season of Al!

It extends from 3 weeks before Father's Day, to 3 weeks afterward. (I never get as much done as I'd like, so that's why I made it so long. I am already behind for this year!!)

It could use a better name though. Al Festival?

Anyway, I have learned a lot from Al over the years and I am grateful. Cheers, people!

Comments (5)

  • last month

    I just avoid transplanting from October till March. Should depend on where you live and your growing conditions (even for indoor plants). No reason to hold to the summer solstice for all transplanting. That is silly.

  • last month

    Silly? First, there is a big difference between repotting and transplanting. Need2seegreen is talking about repotting, not transplanting. You can transplant at any time, but it is still better to transplant almost all foliage plants when they are at peak growth because they can colonize the new soil in the larger pot much faster during the most robust part of the growth cycle.

    While it's true that not all plants grown indoors are best repotted in the two weeks either side of the summer solstice, a very large plurality are. I would guess that >90% of plants grown indoors for their foliage are best repotted in the time frame mentioned. Reason: Due to increasing light intensity and duration as the solstice approaches, the plant will have had some time to start storing surplus energy/food, and, the plant's ability to create food energy is at it's peak when? At the summer solstice. Repotting then ensures the most rapid recovery from root work and/or heavy pruning, both of which are best done within the same time frame.

    Trees and herbaceous plants prioritize their parts, but perhaps it's better to say that the strength of energy sinks has a distinct order: Energy is first allocated to respiratory function, i.e. to maintenance of living tissues, then, to production of fine roots, followed by flower and seed/fruit production, then primary growth (extension of both roots and shoots), then secondary growth (thickening), and finally, the synthesis of defensive chemicals. That defensive chemical synthesis is last in the pecking order means it's the first to be affected when energy production is low. Repotting from late fall thru mid-spring might not kill our plants, but it unnecessarily increases the risk of insect herbivory or infection by disease pathogens. Repotting too early increases the probability of root infections because the slowed growth significantly increases the time required for new roots to colonize the entire soil column.

    Most of us who grow plants have a nurturing bone, and I think most of us would like to be the best caregiver we can be. Simply put, by planning ahead with the plant's best interest in mind, we make reasoned decisions that favor the plant, this, by making allowances for their weakness and taking advantage of their period of high vitality to undertake heavy work like repotting and hard pruning.


    @Need2SeeGreen 10 (SoCal) Just saw your post. Thanks for the kind words.


    Need2SeeGreen 10 (SoCal) thanked tapla (mid-Michigan, USDA z5b-6a)
  • last month

    Well, this interesting to me. Never thought of it. But can really work for how I do “ plant work”.

    I’m way behind on outdoor “ in the ground” work , but it’s getting hot, and my open- lattice potting shed is also hot, it’s at least covered, and re- potting smaller things is not strenuous, but more like happy puttering. But I think I’m past the time for re- potting JM’s ? Because they’re in full leaf now, and I was under impression that all that messing with their roots should be done in early spring before they break dormancy. But I’m worried about them because they’ve been in regular potting soil for several years now, & are big for containers, so likely have compacted & old roots & are at increasing risk of not being able to take up water during the hot summer months.
  • last month
    last modified: last month

    But I think I’m past the time for re- potting JM’s ? Because they’re in full leaf now, and I was under impression that all that messing with their roots should be done in early spring before they break dormancy. It/s true that maples are best repotted in spring between the first sign of budswell and the first leaf buds opening. I currently have a lot of maples (20 perhaps) that should have been repotted last year and weren't. Some of them are seriously rootbound, so I have been following this procedure as time allows:

    * Remove the root/soil mass from the pot.

    * Cut the bottom third of the root mass off with a pruning saw or scissors, depending on how large the root mass is and how thick the roots are.

    * Cut vertical slits in the remaining root mass with a #11 or #24 scalpel. You'll find #11 to be the most versatile for plant applications, though #24 is best for rootwork. Use a utility knife with a fresh blade if you don't want to go the scalpel route.

    * Tease some of the roots away from the sides, then pot in a larger pot until next spring when you can do a full repot with rootwork.

    * Site the plant in a sheltered spot out of wind and sun for a few days. If you see wilting, remove half of the foliage by removing 1 leaf from each existing opposite pair of leaves as per example below. This 'emergency measure' (the entire process) won't fully eliminate the all negative effects of root congestion, but it will allow the plant to operate at a much higher level of vitality than if were to be left to its own devices.

    If you plan on doing a number of repots, you'll find a root rake and a root hook to be invaluable tools for repotting. Also, a root pick made from a wooden dowel rod (5/16" works best) is very helpful for teasing soil out of the roots.

    See the wooden stick (second from right on bottom) or the white nylon tool (fourth from right/bottom) I made from a windshield installation device.


  • last month

    41 North - I was not implying that it was wrong to do re-pots at another time of year, especially if something comes up. I do most things at the wrong time of year! (Not on purpose, it just seems to end up that way.)

    However knowing that this time of the year is probably better, perhaps I can at least prioritize which plants I get to first.

    marmiegard - I've never grown a JM but they're so gorgeous, I may try to do it one day. Good luck with yours!! And I hear you on the heat.

    Hi Al!! That's so interesting about the defensive maneuvers - I didn't know that - wow!