If you have positively excellent drainage (I would set up a raised bed with a gravel/sand/soil mixture) and make sure that it is in full sun (also for quick drying time), I don't see why not...

webkat5,
Thanks for the advice. I can't wait till they are a little bigger so I can plant them! :)

Yes, they certainly can, when given good drainage. There is a botanical garden in the Treasure Valley Foothills in southwestern Idaho (Zone 6) and they have quite a few different kinds of opuntia. I would suggest doing your homework on your plants, though, to make sure that they can survive in your climate zone. Good luck!

If I'm not mistaken, the common name for your cacti is "Prickly Pear Cactus." If I'm right (and photo below to make sure, we're speaking of the same cactus), it's native to all 48 contienental states in the USA and the southern part of Canada. Mines survived outside for 3 years, 12 seasons, floods, droughts, and snow. There are older ones around here. (Philly) Ben Franklin helped his friend Mr. Bartram develop his garden, including a plot of Prickly Pear. We saw it a couple of Springs ago, (They collapse during the winter, then spring up again, eventually) and I put the picture up on a website, so here it is -

[IMG]http://img.photobucket.com/albums/v117/AtWhatCost/blog%20garden%20pictures/Exploringteddies6.jpg[/IMG]
(Did I mention my website is about teddy bears? LOL)

If picture doesn't show up -- sorry about that. Directions on how to upload photos on this site are a bit vague, so I'm not sure if my photo worked, until I post, and then, if I didn't get it right, I can't fix it.

Found out why it didn't post. Here's the picture. The flat things lying on the ground behind bears are Prickly Pears in early spring.
{{gwi:555316}}

Sarah,

I grow Opuntias here in zone 5. We had a horrible, bitterly cold winter this year with a lot of single-digit days and wind chills in the -20 range. They came out fine - they never look particularly great in early spring, but they bounce back and usually are blooming by mid-late June. They're putting on lots of new growth right now, and I even see some buds forming. Here's a pic from a couple years ago...
{{gwi:555317}}
...and some have this flower...
{{gwi:555318}}
...but the plants themselves all look the same to me...

Be sure to put them in a place that's safe from kids and is somewhat contained. I originally put mine out in the area between our sidewalk and the street, but in a few years, it started to get to be a rather large patch and I started to fear some neighborhood kid would fall into them and we'd end up getting sued, so I moved them (OUCH!) up next to our house in a raised bed.

As for good drainage, mine are in just plain old garden soil (midwestern heavy, rich, black earth, with some perlite added) and they do great. I have barberry bushes planted right next to them and they all cohabitate just fine.

Denise in Omaha

joshinator,
Thank you for posting.

That us neat that there are prickly pear cactuses being grown in Idaho.

I have been trying to find information on the cactuses I have but unfortunately I can only find info on Opuntia robusta not Opuntia gigantea robusta. I donÂt know if they are the same thing or not. The man I got them from had them listed on E-Bay as seeds he collected from his Opuntia cactuses that he had transplanted to his yard from a place in NC where they grew wildly. I am thinking that maybe when the cactuses are bigger ( they are only around 1 inch tall now) I will be able compare them to pictures of different varieties of Opuntia cactuses and figure out which ones they are and if they will grow here.

valentinetbear,
Thank you for posting the lovely picture of your cactuses. That amazing that you have had them growing outdoors for 3 years. You definitely have a green thumb! :)

denise,
The pictures of your cactuses in flower are lovely. You must take great care of them for them to flower so nicely.
I bet your hands and arms were sore for a week after you transplanted all of those cactuses! They have wicked spines. Even though mine are just little seedlings so the spikes are these fuzzy innocent looking things I have still gotten jabbed by them a few times. (Whatever variety they are they are going to have huge spikes since the spikes are already one cm long and the cactuses are only around one inch tall)
I wish my cactuses were the same variety as yours. I would love to be able to plant them in regular garden soil.

The man who sold me my cactus seeds is now is selling pads from the same type of cactus. There is a picture of his opuntia cactuses on the site. If anyone would like to look at it I have attached the link.

Here is a link that might be useful: Opuntia gigantea robusta

Sarah, I don't know how large your seedlings are, but the sooner into the ground, the better...they will need quite a bit of acclimation time (and root setting) before winter hits.

webcat5,
My cactuses are various sizes starting at 1/4 inch tall to a little over 1 inch tall. Do you think they will be okay if I plant them now?

Sarah,

You can grow Opuntia outside, but you need to be careful about your soil. I suspect your variety is actually Opuntia robusta. Opuntia seeds are often hard to sprout with the one exception (in my *extremely* limited experience) of Opuntia robusta. I think the cactus seem a bit small to be outside on their own (usually the rule of thumb is the cactus should be 2 years old before going in a permanent bed. However if you have quite a few seedlings, here is what I would do. Prepare your bed, and then plant a subset of your plants outside, have a few potted in a protected unheated area (i.e. a garage window if you have one) that you only water very occasionally and winter a few over inside your home, and see how it goes.

Cactus can be quite cold hardy, but their hardiness depends somewhat on how much rainfall they're exposed to and their tolerance varies depending on species and sometimes individual varieties and location.

In my experience, most of the Opuntia cacti sold at local nurseries are not of a hardy variety.
Some of the hardier varieties:
Opuntia humifusa (O. compressa is a synonym for this)
O. polycantha
O. phaecantha
O. fragilis (the fragile part is that the pads break off the plant easily).

O. humifusa is the East Coast Prickly Pear (and Denise both of those flowers could be O. humifusa - mine looks like the bottom photo.) The others are from the plains, and may be cold hardier, but aren't as tolerant of rainfall.

Here is a robusta link:
Opuntia robusta

There are also some truly beautiful hybrids:

Some sources:
Cold Hardy Cactus - nice pictures
Mesa Gardens No pictures, but many different seeds and cacti available
Intermountain Cactus

This might be useful to you.

Yale

Here is a link that might be useful: cacti