Friday, April 23, 2010

Question for the Hive Mind: Philodendron bipinnatifidum

Got a question at the Philodendron bipinnatifidum profile that I am unable to answer. If anybody knows, please answer here or at the profile (though I'll have to approve comments at the profile, so they'll post more slowly).

Elle wants to know:

I had several large philodendron outgrowing their pots. I had some landscaping done and asked the fellas to plant them in the ground. Well....I think they just dug and stuck, without supplementing my soil which is clay so think I could build and addition to my house with it.

My question is: Should I dig them back up and add better soil? or can I add heaps of compost (horse manure and sawdust + heat composted) to the base of the plant? I'd be so sad to have killed these once beautiful plants. (It's been a couple of weeks and they're looking a little droopy and brownish.)


Kimberly said...

I'm no expert so please get more comments in addition to mine. However, I would dig them up ever so carefully and amend the soil. I'd also make the hole bigger to encourage easier growth while the plants aclimate to the new, tough clay soil. Keep them well watered, but not soggy. I wish you the best of luck!

Nancy in Sun Lakes AZ said...

I agree with Kimberly. I'm not an expert either but I think it won't hurt the plants to carefully dig them up and add amendments to a bigger hole. They will be much happier in the long run.

Don said...

The standard recommendation these days from the USDA extension services, based on Alex Shigo's work, is that when planting trees and shrubs---and I think P. bipinnatifidum basically counts as a shrub---is NOT to add amendments to the backfill, unless you're going to amend a whole bed. It also means that a countainer-grown plant needs to have the container mix removed from around its roots if you want it to survive in clay soil.

When roots encounter a sudden decrease in soil density, they won't penetrate. That means that a plant that's in container mix that's stuck in clay will grow circling roots till it's rootbound, just as if you'd left the container in place. It also means that the hole that the plant's in will fill with water during heavy rains and then won't drain well.

You'd have the best chance of success if you build a raised bed with amended soil, and plant your plant there after removing the container mix from around its roots. The best time to do that is during cool weather, when the evapotranspiratory demands on the plant are minimal, and the plant will have least drought stress while getting established.

Don said...

Oops! That should read, "When roots encounter a sudden INCREASE in soil density..."

Joseph said...

Ditto Don's comment. In addition, I think a lot of people wildly overestimate how poor their soil is -- plants often grow happily in quite dense soils. Transplanting is always a shock, so a little droopyness doesn't necessarily mean they are about to die. If it was me, I'd keep them watered for a season and see what happens before I got the shovel out again.

Don said...

PS You can use your compost best as a 2-3 inch mulch over the roots and surrounding soil. That will help stabilize soil moisture and temperature fluctuations, slow the evaporation of moisture, reduce the germination of weed seeds, and (in the long term) improve the quality of the soil.

DON'T let any organic mulch touch the base of your plant---the bark that's developed in contact with the air needs air circulation to stay healthy, and tends to get fungal diseases (or at worst case, will rot and girdle the plant) where mulch is piled against it and holds in moisture.