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

Friday - November 21, 2008

From: NEW YORK, NY
Region: Northeast
Topic: Cacti and Succulents
Title: Cactus failing to thrive in New York City
Answered by: Barbara Medford

QUESTION:

My cactus seems to be either weak or dying. Its long stems are bending and softer than the rest. What is happening to it?

ANSWER:

Unfortunately, "cactus" is much too wide a term for an accurate answer. You didn't say if your cactus was a house plant or growing outside. In New York, that, alone could answer the question. If it's outside, it probably can't survive the cold temperatures. Because of the heat generated by a large city, New York City has warmer zones than the rest of the state, but you are still in Zone 6a to 6b, which indicates a minimum average freezing temperature of -10 to -5 or -5 to 0 deg. F. Cacti, generally, are desert plants, and don't tolerate very low temperatures. On the other hand, if your plant is indoors and not getting lots of sunlight, it doesn't tolerate that well, either, for the same reason. It is way out of its native habitat. And if it is in a pot without adequate drainage, and/or you are watering it too much, it is probably suffering from that.

Just to demonstrate our point, see this Eduscapes website on Cactus  (Cactaceae).There you will see a number of pictures showing the variety of plants in that family. It further states that there are over 2,000 species that fall in that category.

Three of the genus members of the Cactaceae family:

Mammillaria Sample North American native: Mammillaria pottsii (rat-tail nipple cactus)

Opuntia Sample North American native: Opuntia engelmannii (cactus apple).

Melocactus  According to this USDA Plant Profile, this plant is native to Puerto Rico and the Virgin Islands, but not to continental North America, so it does not appear in our database.

Many plants not even closely related are mistakenly called cactus. We have listed some of these, with native examples and links to pictures.

Yucca Yucca faxoniana (Eve's needle)

Sotol Dasylirion leiophyllum (green sotol)

Nolina Nolina lindheimeriana (devil's shoestring)

Dudleya Dudleya cymosa (canyon liveforever)

Echeveria Echeveria strictiflora (desert savior)

Graptopetalum According to the USDA Plant Profile, this plant is native to Arizona and Texas, but does not appear in our Native Plant Database.

Ocotillo Fouquieria splendens (ocotillo)

So, we hope you understand why we probably can't diagnose your plant's problem, beyond the very broad range of temperature and light exposure.  If you have it indoors, and think the lack of drainage and sunlight might be the problem, we would suggest you repot it in a pot with cactus mixture potting soil (more sand, better-draining), very good drainage, and move it to a sunny window. Beyond that, you can try looking at all the pictures we have linked you to, and if you find one you think is your plant, Google on that plant's scientific name for information on it. 

 

From the Image Gallery


Rat-tail nipple cactus
Mammillaria pottsii

Cactus apple
Opuntia engelmannii

Faxon yucca
Yucca faxoniana

Green sotol
Dasylirion leiophyllum

Devil's shoestring
Nolina lindheimeriana

Canyon liveforever
Dudleya cymosa

Desert savior
Echeveria strictiflora

Ocotillo
Fouquieria splendens

More Cacti and Succulents Questions

Trimming damaged leaves on agaves
February 05, 2009 - Some of the leaves on my agaves are damaged. Can I cut them off? If yes, how can I prevent the wound from becoming infected? Thanks.
view the full question and answer

Saving frozen yuccas from North Carolina
February 23, 2013 - I live in NC and have 2 potted yucca plants on my deck. Every year I have brought them in for the winter. This year, someone told us that we could leave them out all winter. They began to die in the c...
view the full question and answer

Seeds of agave attenuata from San Diego CA
April 16, 2012 - After the agave attenuata bloom dried up there are seeds like thing hanging on the foxtail; do I leave it until it dies or do I chop that down. Are those seeds for propagation. The leaves of the plan...
view the full question and answer

What to do about cold damage to spineless prickly pear?
March 05, 2010 - In Austin, Texas our 'spineless' prickly pear cactus is about 6' wide by 4' tall. In the last severe freeze, the top half flattened out and has remained that way. Should I cut the flattened pads o...
view the full question and answer

Growing Variegated Century Plants in Portugal
February 09, 2011 - Hello Mr. Smarty Plants, I am contacting you from Portugal, because of century plant(Agave americana). I had one of that plants and I collected the seeds, which I planted, but I am quite disappointed ...
view the full question and answer

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