General questions

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Spikylover
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General questions

Post by Spikylover »

1. Our weather is quite hot in the summer and rainy in the winter. Although droughts are usually around 7 months, winter rains are what worries me about planting cacti outside. Even if i used a free draining mix, it's gonna stay wet for a long time. We have tons of opuntias and euphorbias outside and some golden barrels. Does that tell me not to worry?

2. Say i planted in the free draining mix outside, it's not very coherent as clay soil for example. Doesn't that mean that large specimen are gonna tip over with stong winds?

3. I have some epiphyllum and hylocereus cuttings that flowered before rooting and dumped the buds. Isn't flowering very energy intensive? Why would a cutting do that? Is it stress? The old thick hylocereus cuttings that rooted are still producing buds and dumping them while the younger ones are producing new growth. What to do with the old ones?

4. Has anyone tried flood/flush tanks for watering. The idea is to use a large rectangular basin that you flood with water to the level of the top of the soil leave it for a couple of minutes to soak and the flush the tank. That would reduce 1-2 hours of watering to a mere 5 minutes.

5. I place some of my cacti on the metallic roof of a shed. Does the heat of the metal in the sun affect the cacti? Maybe way too much evaporation? Or it supplies a desert like heat?

6. Full sun growth inhibition? I've noticed that with some of my plants that are mature or close: agave americana variegata, euphorbia trigona rubra, mammillaria elongata, echinopsis subdenudata (part sun to full sun) and some more that i forgot. The sun is strong but not as strong as that of the desert. Why are they refusing to grow?

7. European cacti: how do they grow them in pure peat? I understand that cappillary mats are involved to keep the cacti moist but never wet. Is that right? How do they deal with peat as a growing medium?

Thanks for bearing with the long post!

Rachel.
Rachel
Gardening with my mother and father in war ridden Syria
DaveW
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Re: General questions

Post by DaveW »

A lot of plants tend to flower when they get "a near death experience" in order to seed and pass on their genes. Cuttings being an example, but possibly it is better to remove the buds on cuttings since it saps their strength and makes rooting more difficult. I had a couple of 4ft Trichocereus cuttings that flowered for two years without ever rooting when cut from the main plant in the bed which just grew but never flowered.

As to growing in peat, I don't think the Continental nurserymen ever actually allow it to dry out and probably feed and keep the plants growing all year round. The problem comes when they get to the retailer who allows the peat to dry and then it is virtually impossible to wet again. As most of our plants prefer a dryer cooler winter rest to flower, it is therefore better to transfer them from peat to potting soils that will dry yet re-wet easily when required.

Obviously the plants do grow well initially in peat or commercial nurserymen would not use it, but it is not a long term potting soil. I was talking to an English wholesale cactus nurseryman who grew in predominantly peat mixes the same as the Continentals and supplies the garden centres. He said the peat they initially use contains a wetting agent, but obviously over time this is gradually used up.

Plants may take years to grow in the desert, probably growing at nothing like their rate in cultivation. They are also in open ground where their roots can spread out, unlike a pot. In the hottest part of the year CAM plants (Crassulacean Acid Metabolism) as are most Succulents, actually aestivate (the summer equivalent of hibernate) when conditions, particularly at night, are too hot and stop growing until the nights are cooler again.

See link for CAM plants.

https://askabiologist.asu.edu/cam-plants
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Spikylover
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Re: General questions

Post by Spikylover »

DaveW wrote:A lot of plants tend to flower when they get "a near death experience" in order to seed and pass on their genes. Cuttings being an example, but possibly it is better to remove the buds on cuttings since it saps their strength and makes rooting more difficult. I had a couple of 4ft Trichocereus cuttings that flowered for two years without ever rooting when cut from the main plant in the bed which just grew but never flowered.

As to growing in peat, I don't think the Continental nurserymen ever actually allow it to dry out and probably feed and keep the plants growing all year round. The problem comes when they get to the retailer who allows the peat to dry and then it is virtually impossible to wet again. As most of our plants prefer a dryer cooler winter rest to flower, it is therefore better to transfer them from peat to potting soils that will dry yet re-wet easily when required.

Obviously the plants do grow well initially in peat or commercial nurserymen would not use it, but it is not a long term potting soil. I was talking to an English wholesale cactus nurseryman who grew in predominantly peat mixes the same as the Continentals and supplies the garden centres. He said the peat they initially use contains a wetting agent, but obviously over time this is gradually used up.

Plants may take years to grow in the desert, probably growing at nothing like their rate in cultivation. They are also in open ground where their roots can spread out, unlike a pot. In the hottest part of the year CAM plants (Crassulacean Acid Metabolism) as are most Succulents, actually aestivate (the summer equivalent of hibernate) when conditions, particularly at night, are too hot and stop growing until the nights are cooler again.

See link for CAM plants.

https://askabiologist.asu.edu/cam-plants
And how come their cacti don't rot if the mix doesnt dry out completely?
Rachel
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DaveW
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Re: General questions

Post by DaveW »

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greenknight
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Re: General questions

Post by greenknight »

In the nursery the peat mix is never saturated, they grow on capillary matting from which the pots absorb water and stay evenly moist. When you water from above, you get a perched water table - the mix in the bottom of the pot stays saturated until the plant sucks up enough of the water or enough evaporates. See - http://gardening.stackexchange.com/ques ... ater-table

The smaller the pore spaces in the potting mix, the higher the perched water table. With peat, it will be quite high.
Spence :mrgreen:
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Spikylover
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Re: General questions

Post by Spikylover »

Many questions left unaswered
Rachel
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DaveW
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Re: General questions

Post by DaveW »

If your temperatures are OK for growing outside, but you get too much rain in winter there is nothing to stop you putting a temporary plastic roof over them. Whilst we in the UK use greenhouses with roofs and sides in order to control the internal temperature, in many warmer countries they only have a plastic rain roof over the plants with completely open sides all year around. If you want to keep birds or animals out you can use wire mesh for the sides.

https://debraleebaldwin.com/learn/how-r ... ucculents/

Anything you can do in metal you can also do in wood.

http://debraleebaldwin.com/caring-for-s ... hat-to-do/

http://www.succseed.com/vinterhardiga-kaktusar.html

http://www.succulentsandmore.com/2011/0 ... ts-at.html

If your ground is clay and holds water you can grow the plants in raised beds filled with better soil to keep them above the water table, whilst that will keep the plant body clear of the water they will probably root down into the subsoil for stability anyway, or as with Saguaro's produce a wide spreading subsurface root system to provide stability.

http://davesgarden.com/guides/articles/view/1600
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7george
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Re: General questions

Post by 7george »

6. Full sun growth inhibition?
Can be. Many growers shade their greenhouses to avoid burns and stimulate growth. And in habitats plants often live above trees or shrubs or around other large objects that provide partial shade. Your summer is the dry season and in heat many plants from different climates will go dormant for long. I would try to modify your microhabitat around plants to deal with this or water those plants more often during the summer.
5. I place some of my cacti on the metallic roof of a shed. Does the heat of the metal in the sun affect the cacti? Maybe way too much evaporation? Or it supplies a desert like heat?
I would not put my plants there. Pots and roots have to be hidden from heat, shaded as much as possible, like in wooden boxes or even burred.
If your cacti mess in your job just forget about the job.
°C = (°F - 32)/1.8
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Spikylover
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Re: General questions

Post by Spikylover »

7george wrote:
6. Full sun growth inhibition?
Can be. Many growers shade their greenhouses to avoid burns and stimulate growth. And in habitats plants often live above trees or shrubs or around other large objects that provide partial shade. Your summer is the dry season and in heat many plants from different climates will go dormant for long. I would try to modify your microhabitat around plants to deal with this or water those plants more often during the summer.
5. I place some of my cacti on the metallic roof of a shed. Does the heat of the metal in the sun affect the cacti? Maybe way too much evaporation? Or it supplies a desert like heat?
I would not put my plants there. Pots and roots have to be hidden from heat, shaded as much as possible, like in wooden boxes or even burred.
Thanks George that's very helpful! I fear shading the pots will reduce drying time and lead to more complicactions but i will look into that the next growing season.
Concerning a shade cloth, i have a fairly large roll of maybe 15-20%. Do you think i can use it in full sun for all cacti (excluding seedlings)?

Rachel.
Rachel
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7george
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Re: General questions

Post by 7george »

Concerning a shade cloth, i have a fairly large roll of maybe 15-20%. Do you think i can use it in full sun for all cacti (excluding seedlings)?
I think this will work.
If your cacti mess in your job just forget about the job.
°C = (°F - 32)/1.8
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