Barrel cacti in Texas

[Hondoguy]

I live in Austin, TX near the border line between Zones 8 and 9. We usually don't go below 25F but occasionally will get down into the teens. I have several large (12" diameter) Ferocacti (gracilis coloratus, robustus, glaucescens, rectispinus) that I want to put outside in a south-facing location close to the house.

My questions:

1.Can they survive 15F if covered with blankets, frost cloth, etc?
2.Can they survive a wet winter in the ground?
3.I was told be a cactus nurseryman here that they will tolerate cold much better if they are in ground as opposed to pots. True?

Thanks.

[DesertZone]

I think the wet will hurt more than the cold. Kept them dry in the winter, a good gravel mix. The bigger the better, even cold hardy small barrels don't take the cold well, but I don't think you are going to get that cold there?

[iann]

Can they survive 15F if covered with blankets, frost cloth, etc?

I have doubts that any of these would survive 15F, but I can't really judge how effectively you might be able to protect them. Your generally warm days (compared to here!) will help because the ground will mostly stay unfrozen and help to keep the plants alive. Being close to the house will also help. There is probably a lot of variation, but my few species have managed 20F and are still alive. Some of the ones you list are considered amongst the more tender.

Can they survive a wet winter in the ground?

Many Ferocactus species come from winter (or bimodal) rainfall areas so they should have some resistance to winter damp. My own experience has been that the skin tends to mark badly in my winter conditions (damp? humidity? condensation?) and so they need to be kept warm.

.I was told be a cactus nurseryman here that they will tolerate cold much better if they are in ground as opposed to pots. True?

Generally true, but you can take a pot indoors in an emergency

[DesertZone]

I have doubts that any of these would survive 15F

Good point, I think there are some better cold hardy sp.