CactiGuide.com

Sun and water are not working. I proposed the question of How to fatten up my plants on a PC facebook group and the response was all the same. Use Hydro plant foods and over fertilize. So I thought it would be wise to ask the real experts first. How to fatten up the plants. Thanks All
Mike M

From my own experience, Plants from cutting sometime take a bit longer to establish enough root system to support normal growth.
Some cutting can start normal growth in 6 months, some might take 2 to 3 years or even longer.
To encourage more root growth, you can use a bit of Phosphorus fertilizer.

Mike, have the cuttings started to root yet? If not, there's no point in watering until they're starting to grow new roots. If so, the new roots won't be growing at this time of the year anyway, and if I were you, I wouldn't be watering until the next growing season begins in spring. While we're at it, please give me the detailed chemical analysis of the fertilizer you're using. Having learned a lot about ferts from MikeInOz, I'd like to evaluate yours, then provide you with some feedback.

By the way, I'm glad you came here -- I'm sure that advice coming from Facebook will do more harm than good.

Applying a mycorrhizal inoculant might help, the fungi increase the absorptive area of the roots. In my limited tests, inoculated cacti were a little more robust than those not inoculated.

greenknight wrote: ↑Sat Dec 03, 2022 9:02 am Applying a mycorrhizal inoculant might help, the fungi increase the absorptive area of the roots. In my limited tests, inoculated cacti were a little more robust than those not inoculated.

Would mycorrhizal fungi that Garden Centers sell for veggy garden work or you need specific strain?

Sorry for high jacking the thread.

The general-purpose mycorrhizal blends should contain some that are compatible with cacti. I recommend products containing Trichoderma harzianum especially, as it protects roots from fungal diseases, actually attacks and kills pathogenic fungi.

greenknight wrote: ↑Sun Dec 04, 2022 12:58 am The general-purpose mycorrhizal blends should contain some that are compatible with cacti. I recommend products containing Trichoderma harzianum especially, as it protects roots from fungal diseases, actually attacks and kills pathogenic fungi.

Okay, I'll hijack Mike's thread too...

I've been skeptical of the idea that mycorrhizal fungi do significant good for cacti growing in pots, but I'm willing to rethink it. Thing is that out of the 68 cacti I have in my collection, I'm growing 64 in a soil-less pumice and granite gravel mix. Would Trichoderma harzianum support such a mix? If so, I may introduce it to the collection in the spring.

Trichoderma spp are highly adaptable and found in nearly all types of soil, and I've read about T. harzianum being used in hydroponic growing. so it probably would work. It might be that a little organic matter would enhance its growth, though. I'm currently using an organic fertilizer that contains inoculants, both fungal and bacterial, humic acid, and microbe food (sugars). I'm going to start a new thread about that, we've hijacked this one enough , but here's a link: https://www.amazon.com/stores/page/7B22 ... f_=ast_bln

Provide as much sun as possible.

Hi Guys. These are all fully rooted cuttings. These came 2 in pot from HD 3 months ago. They all have decent size root balls. I have 5 other PC's in the greenhouse that are also fully rooted and they have grown tall and thin also. I'm only having an issue with my PC's. All my other 1200 plants are doing fine.
Mike M

They’ll most likely need to grow some bigger roots and you could use miracle grow tomato fertilizer which will definitely fatten them up