No, not when they're not in growth (and most cactus are not in winter). When they are in growth, a feeding once a month is fine, but you'll get lots of opinions on that.

I personally do not fertilize during winter. I have to keep my plants indoors for about 6 months, and try to keep my summer growers more or less dormant to prevent etiolated growth (I use T5 lights which work well but are still no substitute for sunlight for preventing etiolation). I do not fertilize and I water infrequently. If you want your plants to put on growth during winter, you can fertilize, water frequently and provide a very strong light source to try to mimic the growing season environment.

In a soil-less mix, one that you're frequently watering, I would recommend that you continue fertilizing at a reduced strength dose. If you're flushing the mix with every watering, your plants shouldn't experience any detriment from salt accumulation.

Josh

Just curious- what kind of potting medium are you using? Because if it's sand or perlite or bark it might vary but basically I agree with Josh. Perlite can stay wet sometimes and sand too. Rocks or bark you can just do what Josh said.

I wonder why it's recommended that a plant in dormancy/not in growth would need feeding, let alone be given it.

There are a number of succulents which are in growth in the winter, and those should be fed, but for those not active, no feeding is needed or necessary.

It's just that people like to take care of their plants- watering them is fun. Hopefully you don't harm them in the process.

I even fertilize outdoor containers of maples, conifers, willows, et cetera, over the Winter. Not much, but regularly.

Josh

Cooper,

Grow enough plants that die at the slightest touch of regular watering/feeding in the wrong season, and you'll understand that it's because I do care for my plants that I do not regularly water/feed when they're not in growth.

Josh,

I frankly announce that I'm slow to change concerning growing practices that have worked for me for nearly 20 years, and I hope I'm still learning, but I see no benefit watering regularly / feeding at all a dormant Cyphostemma, for example. I know I can't get away with that here, and I'm sure the same activity in San Diego would kill the plant, too. Fortunately, most of my collection grows most of the year. I don't feed our maples, hawthorns, lilacs and birches when they're leafless. I've heard that that's detrimental to their health (so sayeth a master gardener), but I actually haven't confirmed this in the tree books which I have (and haven't yet read).

Hi all,
I water a bit in spring and a bit more in the summer. From the end of september till next spring nothing except a bit of spraying. I never fertilize, but repot every -say 3 - years. Most of them do fine on that.
greets Harry

Caudex1 has said he never fertilizes. One could make the argument he has some of the nicest specimens on this site......

For the topic at hand, I'm with Jeff. I don't fertilize while the plants are dormant.

Rob

I have another dumb question but since I'm curious I'll ask it anyway. My plants are inside, the temperature is kept the same the year around, when there is no sunlight I use artificial lighting. How do inside plants know when it's time to go dormant?

I'll admit I'm a little heavy on the watering, feeding thing but but with cacti if everything's bone dry then it'll just shrivel up and die from dehydration.

Emee- the light and the temperature. If you have a cooler spot that might help. I keep mine growing all year- see!

With all due respect, Opuntias are not the best genus to use in a discussion regarding dormancy, as they're the scandals of the cactus world wrt growing opportunistically.

Thanks everyone!

Jeff, if you have a fraction of compost in your plant mixes, then you are providing them nutrients. My mixes offer no nutrients, thus I must provide for them, albeit at much reduced (though regular) Winter rates.

Josh

I missed that, Josh - I thought we were talking only about supplemental fertilizer. I indeed do have more than a fraction in my mix.