Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Monday - June 22, 2009

From: Austin, TX
Region: Southwest
Topic: Watering, Cacti and Succulents
Title: Why are the leaves of my century plants yellowing?
Answered by: Jimmy Mills

QUESTION:

I am taking care of the Agaves (century plants) for my condo community here in Austin. They are planted in 18" or 20" pots. A couple of the plants have leaves that are yellowing around the bottom. At first I thought it might be under watering - I soak them once every other week for about two minutes. Now I'm starting to think it might be over watering. They are all lined up facing West and the ones on the north end of the line up are the ones experiencing the most yellowing. Any ideas?

ANSWER:

The term Century Plant is applied to eight different Agaves in our NPIN Database.  Since Agaves are adapted to surviving in dry environments, over watering is probably more of a threat in your case than under watering.

While some yellowing of lower foliage is normal in Agaves, this could be a case of salt burn which is a result of build up of soluble salts in the soil. Another sign of salt build up is the accumulation of a white residue on the outside of clay pots or on the rim of plastic pots and on the surface of the soil. This condition can be taken care of with leaching which in effect flushes the excess minerals out of the pot.

To accomplish this, give the plants a normal watering and wait  for thirty minutes to an hour. Then pour an amount of water that is four to five time the volume of of the soil in the pot, allowing it to drain through the hole in the pot. Discard the drained water, and wash out the saucer before returning the pot to it.

I'm including a link to an article on watering guidelines from  Colorado State University Cooperative Extension, and a link that describes the leaching process.

 

 

 

More Cacti and Succulents Questions

No blooms on Spineless Prickly Pear in Austin
June 07, 2012 - I've had a spineless prickly pear planted in the shade for about 3 years. It has done just fine there, but has never bloomed. I recently moved it to a full sun location(I'm in north Austin) and cove...
view the full question and answer

Getting rid of Adams needle (Yucca filamentosa)
June 24, 2009 - My friend is changing her flower beds around and is wanting to eliminate an Adam's needle that has been there for several years. She has already dug it up and now is trying to get rid of all the new...
view the full question and answer

Century plant dying after bloom
April 06, 2006 - Help!! I want to save my Century Plant from dying. I have already lost one and I don't want to lose this one. Can cutting the stalk before it gets too big save this beautiful plant? Please, pleas...
view the full question and answer

Both large and small Century plants putting up stems from Cayucos CA
November 18, 2013 - I have a Century Plant that is sending up a stem. I am excited to see it bloom. I noticed that one of the small pups, about 4 inches tall, is also sending up a stem. I have not found a mention of pups...
view the full question and answer

Agave in a vase of water in Tacoma WA
July 19, 2009 - I have a agave plant that is in a vase of water only. It was given to me about 3 years ago, still growing but rotting inside of the water. Is it suppose to be in dirt? How to I transfer into a pot ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.