Fertilize Buds in January?

[loyall]

I purchased a small Mammillaria microhelia last January and it blossomed in February. It lives on a south window sill where it gets some direct sunlight. It more than doubled in size in the first year (see before and after photos) and now it is January again and it has set some new blossoms. There are a number of new buds just beginning to pierce the stem in the axils between the tubercles around the top of the plant. Even though I reduced watering and stopped fertilizing in September, should I now begin to fertilize or just watch the flowers, and wait for March to increase water and fertilizer? Perhaps there is no correct answer. Even in these winter months I am watering this four-inch pot every three weeks.

Cactus blossoms_20210210_03.jpg (90.55 KiB) Viewed 1107 times

M microhelia_20211008_07.jpg (78.85 KiB) Viewed 1107 times

[7george]

If there is no real growth (not flowers) there is no need to fertilize. The flowering success depends on previous months and season care. The mature mammillaria will bloom even without any watering winter time. Fertilizing is better started since April but if you water now is your choice what kind of water to use for this.

The plant looks very expanded for the time of the year. I'd be concerned that inability to intake more water from the pot would cause soil to stay longer wet and to cause root rot eventually. Maybe your conditions (like home temperature) are different so it's up to you to decide about the care.

[loyall]

Thanks 7george.

If there is no real growth (not flowers) there is no need to fertilize.

Understood.

[mikethecactusguy]

I really like the wire support you fashioned. Are you concerned the plant will tip?

[loyall]

Yes. The taller this cactus grows the more pronounced the tilt toward the light. The wire is a guide for periodic turning to keep the plant vertical. It works surprisingly well. I rather suspect that if I did not turn it, the plant would prefer to lie down on my window sill.

[loyall]

Well, it is now mid-February and my M. microhelia is blossoming. I have to turn it daily to keep it vertical. This is the second year it has blossomed in Feb. Is it unusual for M. microhelia to blossom in February?

M microhelia_20220211_21.jpg (97.21 KiB) Viewed 946 times

[MrXeric]

I rooted a small cutting of M. microhelia last year and it bloomed for the first time this week.

It's been forming buds since early January but I'm not sure if February is the typical month it blooms since we're in the middle of a winter heat wave here in California and the heat may have triggered early blooms for me. ADBLPS lists one locality of this species as blooming between March and April in Europe.

[loyall]

Thanks MrXerik,
My microhelia lives on my windowsill here in Maine where its January temperature was between 60-65°F when the sun was not shining on it. I find it interesting that our two plants with such different environments blossom at the same time. I notice that your plant has longer and denser spination as well as solid-colored blossoms. Do you think that is due to environment or species variation? Perhaps hybridization?

[MrXeric]

My microhelia lives on my windowsill here in Maine where its January temperature was between 60-65°F

That's more or less what my plant was getting for most of the winter here, with nights just above 40F, a few sprinkled mid 30s here and there. Then the heat wave came in with 90F days and mid 50 nights. Luckily, "winter" returns on Tuesday (58F/40F with rain ).

I notice that your plant has longer and denser spination as well as solid-colored blossoms. Do you think that is due to environment or species variation? Perhaps hybridization?

A little both, I think. I keep my plant in direct sun outdoors all year long, and that tends to promote denser and stronger spines. Flower color for this species seems to be variable, ranging from creamy-white to purplish. I would certainly not discount the possibility of hybridization, since I don't know the origin of this plant (it was a free cutting from an online plant order). Further, I haven't watered this since November, so the spines look denser than they are. I was pretty heavy-handed with water on this plant, so when it was in growth you could see some of the green stem. I prefer the look of it now so I will be keeping it thirsty in the future.

[DaveW]

Mammillaria microhelia and Mammillaria microheliopsis are usually considered synonymous, only really differing in flower colour in what is a variable species.

However if you look online you will see pictures with either name on them. If the two are combined M. microhelia takes priority being published earlier. Apparent changes in flower colour in some species can depend on whether a coloured midstripe is present on the petals and how wide it is. Also if the midstripe varies in width in different years the flower colour intensity can appear to do so too.

Mammillaria microhelia was originally the yellow flowered form.

http://www.llifle.com/Encyclopedia/CACT ... microhelia

Mammillaria microheliopsis the pink flowered form.

http://llifle.com/Encyclopedia/CACTI/Fa ... oheliopsis

[loyall]

Thank you DaveW for the commentary and links. I found it instructive. My 16cm tall fellow seems to have the habit of microhelia and the color of microheliopsis variety.

M microhelia_20220214_07.jpg (97.14 KiB) Viewed 875 times