Thursday, February 17, 2011

Agaves in the rain

After seeing my post on my temporary rain shelter for cacti, a reader asked what I do to protect my agaves. The short answer is: nothing. However, things are never as simple as they seem, so here is some background information.

About half of our agaves are planted in the ground in mounded beds. This ensures that the crown and most of root system are above grade so water can drain freely. The soil in our mounded beds is heavily amended with pea gravel, sharp sand and crushed pumice. Even if these beds get a good soaking, there is never any standing water that might lead to rot.

110216_agave_desmett_schidig
Agave filifera subsp. schidigera (left), Agave desmettiana ‘Variegata’ (center top), and Aloe striata (right). The highest parts of this mounded bed are close to 2 ft above grade.
110216_agave_blue_glow_vict2
Agave ‘Blue Glow’ (left) and Agave victoriae-reginae (right) hiding under the leaves of a ponytail palm (Beaucarnea recurvata)
110216_agave_blue_glow_vict
Same two agaves from a lower perspective.
Even though it may not look like much, the overhanging leaves do provide shelter from the rain, cold and sun.
110216_agave_vilm
Agave vilmoriniana in the driveway-side succulent bed. While not planted on top of the mound, it’s still sufficiently raised to ensure good drainage.

Some of our potted agaves are out in the open year round. The key to preventing rot caused by too much water is to make sure they are in the right container size. As you can see in the photo below, both the Aloe marlothii on the left and the Agave americana 'Mediopicta Aurea’ on the right fill their pots so there is no excess of soil that would get saturated in a downpour and stay wet for an extended period of time.

110216_agave_am_mediopicta_aurea
Potted Aloe marlothii (left) and
Agave americana 'Mediopicta Aurea’ (right )

Other potted agaves are on the edge of our front porch where they are protected by the roof overhead. If rain is accompanied by strong winds—as was the case this morning—they do get a bit wet but since the potting soil is loose and free draining, that doesn’t really matter.

110216_potted_agaves
 

I have yet to loose an agave to rot caused by excess water, which leads me to believe that they are far more water-tolerant than other succulents, especially cacti and some aloes. If I lived in a climate that gets more than 30 inches of rain a year I would be more concerned, but here in the Central Valley where we get a mere 20 inches, there’s no reason to be excessively worried.

Note: For a post on protecting tender succulents from frost, click here.

3 comments:

  1. Nice post about plants I'll never grow unless I move to a house with more south-facing windows. =)

    One clarification on agaves (and any other plant that doesn't like wet soil) in pots: the idea is you want the plant's roots to fill every inch of soil, so water is sucked out quickly, and they still want more. At least that's how I understand it.

    Also, why do you have a saucer under that one pot? Seems risky -- or would be if you got more rain I guess.

    ___________________________
    It's not work, it's gardening!
    .

    ReplyDelete
  2. Alan, yes, if a pot is mostly filled with roots, excess water will simply run off instead of being stored in the soil.

    The saucer actually has three holes along one side. It's usually positioned right on the edge of the flagstone patio so excess water can run out of the saucer into the planting strip.

    ReplyDelete
  3. Thank you so much! I found this post very useful for me since I started to grow several agave in my near-Seattle garden. Water rot is my main concern. Also, I'm trying to decide whether to take my plants indoors for winter or just move them under a cover.
    Thanks again!

    ReplyDelete