thanksgiving cactus- need help with an issue

[MikeInOz]

The basic rule of thumb for a well-balanced fertilizer is "P lower than N, K higher than both". This applies to all ornamental plants, not just cacti and succulents.

That depends. Some plants require much higher N levels if they are fast growers. The usual 10-15N - 3P - 8.5K works well for most leafy plants and is what is mainly what's used in the nursery industry. At least during the warm, bright season.

[solj3]

Thank you for the advice. I'll follow your instructions for repotting. The mix just arrived today. I'll start the process this weekend. Yes, about the fertilizer, I'll see what I can find with those NPK numbers and reach out on this thread when I have it on hand. Admittedly, I'm not familiar with proper use and knowing when is the best time to fertilize as well as how often should I fertilize my cactuses in one year. I'd welcome any advice on that as well. Thank you again everyone

[jerrytheplater]

I repotted my Christmas cactus in early summer using a 50/50 mix of fine and coarse Orchid potting mix bought at Home Depot. I potted it in an orchid pot with slots on the sides. It fell out of the pot twice because the mix would not hold the plant in. But after staking it and being careful not to knock it, it is now rooted firmly in and the roots are coming out of the pot all over: top, sides and bottom. I"ve got flower buds just forming now. It'll probably bloom for Thanksgiving.

[solj3]

Day 1 after repotting into the new mix. Will wait until Saturday to water it. It looks a bit droopy after manipulation into the new mix but I have a feeling it's going to bounce back. I tried looking for fertilizer with those listed NPK numbers but no luck. I went with jobo fertilizer spikes which has good reviews for cactus growth on Amazon. Those spikes should arrive in the mail today.

[Steve Johnson]

Day 1 after repotting into the new mix. Will wait until Saturday to water it. It looks a bit droopy after manipulation into the new mix but I have a feeling it's going to bounce back. I tried looking for fertilizer with those listed NPK numbers but no luck. I went with jobo fertilizer spikes which has good reviews for cactus growth on Amazon. Those spikes should arrive in the mail today.

You're talking about Jobe's fertilizer spikes. The ones I see on Amazon are Fertilizer Spikes for Flowering Plants (NPK 8-9-12), Succulent Fertilizer Spikes (NPK 2-8-8), Flowering Plant Fertilizer Spikes (NPK 10-10-4), Fertilizer Spikes for Azalea, Camellia, and Rhododendron (NPK 9-8-7). The list goes on, but none of them are good for cacti. Remember the basic rule -- P lower than N, K higher than both. Unfortunately I don't have any experience with your Christmas and Thanksgiving cacti, so I can't tell you if they need to be fertilized in the fall and winter. Before you commit to fertilizing, hopefully one of our other members who grow them will A. advise you on when you should do it, and B. give you recommendations on a fertilizer that is appropriate to growing jungle cacti like your plants.

I repotted my Christmas cactus in early summer using a 50/50 mix of fine and coarse Orchid potting mix bought at Home Depot. I potted it in an orchid pot with slots on the sides. It fell out of the pot twice because the mix would not hold the plant in. But after staking it and being careful not to knock it, it is now rooted firmly in and the roots are coming out of the pot all over: top, sides and bottom. I"ve got flower buds just forming now. It'll probably bloom for Thanksgiving.

Jerry -- regarding fertilizer and when to fertilize, what would you recommend for solj3?

[solj3]

ok, understood. thank you steve johnson. ill return those jobes spikes and hold off on fertilizing until i hear back from this group. in the meantime, ill keep looking to find the right npk fertilizer for my cactus that follows the rule: p lower than n, k higher than both

[jerrytheplater]

I fertilize my Christmas cactus every time I water it, which in my house is weekly. I do let it dry out a bit after it is done blooming. I'll let it go two weeks between waterings for a month or two. Since you just repotted, you won't need to fertilize right on the first watering. I have been using an Orchid fertilizer, Better-Gro Orchid Plus which is 20-14-13. I water it at 1/4 tsp per gallon. I pack the fertilizer into the measuring spoon. I use rain water to mix the fertilizer. And now I am experimenting with something new:

Waldor Orchids in Linwood, NJ is selling Orchid Nerd fertilizers that say they are following research from Michigan State University. I have been trying to read the papers on this research, but have not found them yet. I just bought some of this fertilizer today and hope to get it next week. It is 12-1-1 with 10% Ca and 3% Mg. It is the K Lite formula. I may add extra K, or try it like it is. I'm already using a MSU type mix similar to it on my two orchids and Christmas Cactus, it is a 13-3-15 with 8%Ca and 2% Mg. My daughter bought it on my recommendation and I took a gallons worth.

Here's an article probably from the late 1970's on how to stimulate your Holiday cactus to bloom. I just found it today in a book on houseplants. The information is still correct. I've had my Christmas cactus outside overnight for about 3 weeks now. I have blooms all over the plant. Our nightime temps are in the mid 40's now. No frost yet. Don't let your plant get frosted at all.

The article:

X-mas Cactus Bloom stimulation.jpg (55.6 KiB) Viewed 6969 times

[jerrytheplater]

I was just looking at your pot Solj3. It looks pretty big. These plants like to be root bound and I'm thinking you have overpotted your plant. I had mine in the 4" pot it was purchased in for at least 5 years. It was solid roots and almost no potting mix when I repotted. I went up in size on my pot to maybe a 5" pot. But it was shallower.

It would not hurt your plant to repot again into a smaller pot-unless I am really missing something and your plant is bigger than the photo shows.

[greenknight]

I was just looking at your pot Solj3. It looks pretty big. These plants like to be root bound and I'm thinking you have overpotted your plant. I had mine in the 4" pot it was purchased in for at least 5 years. It was solid roots and almost no potting mix when I repotted. I went up in size on my pot to maybe a 5" pot. But it was shallower.

It would not hurt your plant to repot again into a smaller pot-unless I am really missing something and your plant is bigger than the photo shows.

When I used to grow those, I'd start small cuttings in 2.5" pots (7cm) and they'd bloom the next year - one or two blossoms. Then I'd move them into 3" pots for a year or two, or put several into a 4" pot - but I always started them in small, individual pots, and kept them tightly potted. They grow well and bloom prolifically treated this way.

[solj3]

thank you jerrytheplater for the helpful information. my cactus has started perking up which im happy about. i watered it last night and glad to report no snow mold growth this morning. here is a photo day 6 after repotting in new christmas cactus repot me mix. i think ill keep it in its current pot just becuase its been living in that pot for 2 years and im too afraid to move it again. thank you for sharing what you do to fertilize your cactus. ive been looking for slow release spikes to make things easy but im open to trying what you do by adding it to the water. ill see if i find the right one that follows the npk rule: p lower than n, k higher than both. thank you again!

[Steve Johnson]

ill see if i find the right one that follows the npk rule: p lower than n, k higher than both.

Jerry's first post on 10/18 gave me an idea...

Unlike desert cacti, Christmas/Thanksgiving cacti and orchids may have similar nutrient requirements. If that's the case, I think this MSU slow-release Orchid Fertilizer on Amazon should work:

https://www.amazon.com/Orchid-Fertilize ... 9hdGY&th=1

Check out the fert's guaranteed analysis:

MSU_orchid_slow-release.jpg (129.57 KiB) Viewed 6884 times

That nutrient profile looks good, and certainly a darn sight better than anything coming from Jobe's and Miracle-Gro. I'd say go for it.

[solj3]

thank you steve johnson. ill give it a try!

[Steve Johnson]

thank you steve johnson. ill give it a try!

You're welcome, and please let us know about how things are going for you!

[jerrytheplater]

ill see if i find the right one that follows the npk rule: p lower than n, k higher than both.

Jerry's first post on 10/18 gave me an idea...

Unlike desert cacti, Christmas/Thanksgiving cacti and orchids may have similar nutrient requirements. If that's the case, I think this MSU slow-release Orchid Fertilizer on Amazon should work:

https://www.amazon.com/Orchid-Fertilize ... 9hdGY&th=1

Check out the fert's guaranteed analysis:

MSU_orchid_slow-release.jpg

That nutrient profile looks good, and certainly a darn sight better than anything coming from Jobe's and Miracle-Gro. I'd say go for it.

Steve,

This is the fertilizer I told my daughter to get. But, she got hers from Waldor Orchids via Amazon. The price is much cheaper through them, but I was not happy with the granules and dust in the same bag. Too hard to get a representative mix when scooping it out. I ground hers to a uniform powder, but it absorbs humidity very rapidly and liquifies. Still usable, but hard to know how much you are using. I intend to dissolve the bags of mine and make a stock solution.

Notice the derived from statement. No mention of any phosphorous compounds. Yet the analysis shows phosphorous is there. Incomplete information. Trade secret?

[jerrytheplater]

Jerry's first post on 10/18 gave me an idea...

Unlike desert cacti, Christmas/Thanksgiving cacti and orchids may have similar nutrient requirements. If that's the case, I think this MSU slow-release Orchid Fertilizer on Amazon should work:

https://www.amazon.com/Orchid-Fertilize ... 9hdGY&th=1

Check out the fert's guaranteed analysis:

MSU_orchid_slow-release.jpg

That nutrient profile looks good, and certainly a darn sight better than anything coming from Jobe's and Miracle-Gro. I'd say go for it.

Steve,

This is the fertilizer I told my daughter to get. But, she got hers from Waldor Orchids via Amazon. The price is much cheaper through them, but I was not happy with the granules and dust in the same bag. Too hard to get a representative mix when scooping it out. I ground hers to a uniform powder, but it absorbs humidity very rapidly and liquifies. (like Miracle-Gro) Still usable, but hard to know how much you are using. I intend to dissolve the bags of mine and make a stock solution.

Notice the derived from statement. No mention of any phosphorous compounds. Yet the analysis shows phosphorous is there. Incomplete information. Trade secret?