[Arid_gardener] saguaro cactus seeds - what to do after sprouting

[Janet Howe]

Original Question:

On a trip to the canyons in May we purchased a saguaro cactus seed kit.
It appears that all the seeds have germinated.  The tiny pot -- about 1
1/4" across -- is full of saguaros, all clumped together and some about
1/4" high already.  They appear to like Florida sunshine and my kitchen
window ledge!

Should I leave them clumped together, or should I try to separate and
transplant them individually?  

Your advise will be much appreciated.

Roy Nash
Naples, FL

Answer:

Roy, congratulations, you must be quite the gardener!  To care for your
little starters, go ahead and separate them -- carefully.  If you don't
have more of the starting soil that came in the kit, make sure they go
into a cactus type soil, or preferably a mixture of cactus soil, sand
and pumice if available (mix at a ratio of 1:1:1).  Any standard
household potting soil will hold too much moisture.  The most important
thing is to provide very well draining soil, and water very sparingly --
they'll pick up quite a bit of moisture just being in Florida.

To separate, I'd gently use a pair or tweezers or something similar, and
a small blunt object to help separate the roots, then place into the
prepared soil.  Take care not to pack the soil around the roots too
firmly, but enough so that when you water, they're still supported.  

Keep them in very bright light, and water only occasionally -- probably
no more than once a month or once very couple months, and allow all the
water to drain straight through, don't allow them to stand in water for
any length of time.  

If you feel compelled to fertilize (I always do!), use a very dilute
solution designed for cactus & succulents during their growing season,
in the fall & spring.  Be careful not to over fertilize, as that may
lead to spurts of grown rather than nice steady growth.  One source in
my library actually recommends not fertilizing at all, rather changing
the soil annually instead to provide needed nutrients -- they really
don't need much.

Good luck with your cactus!

Janet Howe
Master Gardener volunteer
Maricopa County Cooperative Extension