Do you think it's time?

[Aichybatoal]

Alright, I've had my cacti for about 2 years now, and I've learned a lot. I've lost one to mealybugs, and it will never happen again. I lost another to rot, which... was actually entirely not my fault to begin with...! But I've also had to do a couple of repots, and we all know how much fun THAT can be, right? Yeah... Well, anyway, I've just got a simple advice question. My Balloon Cactus (Noto. magnif.) is looking a little big in his 4.5 inch terra cotta pot, and I kind of think it's time for a repot. But, obviously, I'd like to avoid it if it's not yet necessary, because of all the work and preparation involved. What do you think? Also, would you mind telling me if it looks like it's growing correctly/healthily for a Balloon cactus? Take a look at the picture and give me your opinion.

[Steve Johnson]

Alright, I've had my cacti for about 2 years now, and I've learned a lot. I've lost one to mealybugs, and it will never happen again. I lost another to rot, which... was actually entirely not my fault to begin with...! But I've also had to do a couple of repots, and we all know how much fun THAT can be, right? Yeah... Well, anyway, I've just got a simple advice question. My Balloon Cactus (Noto. magnif.) is looking a little big in his 4.5 inch terra cotta pot, and I kind of think it's time for a repot. But, obviously, I'd like to avoid it if it's not yet necessary, because of all the work and preparation involved. What do you think? Also, would you mind telling me if it looks like it's growing correctly/healthily for a Balloon cactus? Take a look at the picture and give me your opinion.

A critical limitation since I don't grow the species, but yours looks really good to me. Maybe a bit under-potted, although it's hard to tell what's going on below-ground. The only way you'll know for sure is to unpot the plant first. If the pot is completely full of roots, you may want to think about going to a 6" pot -- my pot-sizing rule of thumb is to have a margin of about 3/4" around the root ball.

Now let's talk about your pot. That's terracotta with a nasty white deposit from the Calcium bicarbonate building up over multiple waterings with hard water. If you can store up rainwater and water your cacti with it, go with that. An excellent fallback is to acidify your tap water. I've been diluting my water with 5% white vinegar for about 2 1/2 years, and believe me -- it does wonders for all plants, not just cacti. Dilution depends on the pH of what's coming out of your tap. The municipal water supply running through my area is about 7.9 pH, and I add 2 tsp. vinegar per gallon after I put in my fert. Final pH for watering is 5.5 or thereabouts. If you don't want to go to the lengths people like me do, I think you'd be okay with 1 tsp. per gallon. I'm not a fan of what rooting behavior does to porous clay when we grow cacti, so you may want to think about going over to plastic or glazed ceramic pots.

[hoteidoc]

For me, that's near perfect -- in potting ratio & plant health! I still use terracotta, but more for species that are known to be very rot prone, or ones that I've killed d/t overH20ing. I probably would repot by end of Summer tho. These guys (N. magnif.) are prone to losing roots d/t lack of H20 during the Winter, so they will get a light H20ing occas. then. Terracotta would be a "safeguard" against a Winter rot.

[Aichybatoal]

Excellent advice, both of you! And thanks a lot for that great bit of science, Steve! Still, though, I do always water them with purified water (from one of those stupid filter pitchers), but I can see how that would still deposit minerals. Thanks again!

[DaveW]

Not sure what you mean by "purified water" but if you mean using water from water softeners it is not a good idea for plants long term:-

http://homeguides.sfgate.com/watering-g ... 38688.html" onclick="window.open(this.href);return false;

http://apps.rhs.org.uk/advicesearch/Pro ... px?pid=691" onclick="window.open(this.href);return false;

Always best for plants if you can catch rainwater and use that. If not if you have a dehumidifier or condensing tumble dryer the water from that is distilled water as is that obtained defrosting the fridge and often enough if you only have a few plants.

[Aichybatoal]

Sorry for confusing you! We get Lake Michigan water, so luckily, we don't have to deal with those giant Morton salt cubes or hard water at all! But, of course, the tap water is still a little chlorinated, so we got a Mavea filter pitcher to remove any remaining impurities. It works great, and after months of drinking that water only, I can actually taste a major difference between it and regular tap water. But, you're correct, it's still not distilled, and rainwater is always best for plants! I just use this extra filtered water as a convenience, and because it's a step up from straight tap water.

Also, another thing: shouldn't this cactus be putting out flowers regularly by this time? I've seen smaller specimens of the same cactus flowering in stores (no, they were not "straw flowers"... Ugh), and mine certainly looks mature enough, but I've never even seen so much as a bud. Does it need more sun, or is it just not ready yet? Thanks for all your advice.

[greenknight]

What temperature was it where it spent the winter? Few desert cacti will bloom if they're wintered at above 55 f. http://www.cactus-art.biz/note-book/Dic ... r_rest.htm" onclick="window.open(this.href);return false;

[DaveW]

Plants are like people, some mature and procreate at an earlier age than others! Normal genetic variation will mean some examples of a species will flower before others.

Your plant does not look badly grown so I expect it will flower in due course. Plants also often flower earlier the harder they are grown since they can make vegetative growth at the expense of flowers. As I have said before "near death experiences" make them keen to pass on their genes to a new generation!

However I would just give your plant time rather than doing anything that radical.