Amaryllis: trimming thick basal plates

Asked February 6, 2019, 1:43 PM EST

I have thoroughly read the UMN Extension amaryllis article. I have looked *everywhere* for information on the problem of thick basal plates developing on amaryllises, and the only thing I've found is on davesgarden: This is a very interesting thread, and I was one of the participants, and continue to follow the advice given there when it looks like my amaryllis are getting thick plates on the bottom. But because I've only ever seen this information in this one place, I feel like I don't have enough references. Do you know about this issue, and do you have any information about it? Are you able to point to any other resources, including books? Many thanks, JLC

Otter Tail County Minnesota

3 Responses

Thank you for the question. This is not a problem I have encountered before so I attempted to find research based publications on how to best treat a bulb with thickened basal plate. I didn't find anything, except for information on the importance of basal plates for the growth of the bulb which I assume you already know.
I reached out to the Master Gardener group to see if anyone could provide more resources but didn't get any results to pass on to you.
If I learn more in the following days, I'll pass it on to you.

The only published information I've been able to find since posting my question is this, which I accessed through the "Look inside" feature at Amazon, in Read, Veronica M., Hippeastrum: The Gardener's Amaryllis (Royal Horticultural Society/Timber Press Plant Collectors Guides Series).

“If the basal plate is more than 0.5 in. (1 cm) thick or shows any sign of damage, then remove a sliver of it. The basal plate can be a popular hiding place for a range of insects which can cause serious damage and sometimes prove fatal. Very thick basal plates may also impede new root growth.”

After this comment she goes on to potting procedures. There is nothing about trimming the trimming process (like what to do after - cure, or not cure? growth hormone, cinnamon, PO3, physan...?), or how much to trim. It does sound, however, as though that basal plate should be kept to less than 1 cm in thickness, and if one catches it at this point, just taking off about half of that would meet the "sliver" description.

I have had at least one or two declining bulbs be rejuvenated by trimming the basal plate; even though I think I took off more than I should have, they certainly recovered.

Apart from Read's very brief comment, the fairly detailed advice given on the davesgarden site is the only thing I've ever seen. Please do ask other Master Gardeners if they know any hippeastrum experts - breeders, growers - who know about this. I would really appreciate more input.

Many thanks!

I did ask the entire statewide master gardener group and received no more information. I'm sorry, but I have nothing to offer more than the information you found.