Fertilizer and Heat
- Thread starter AZbonsai
- Start date
milehigh_7
Mister 500,000
It does have an impact. Are you using organic fert? Extended release such as Osmocote? If so what brand? Also be aware that roots stop growing above a certain temp. I had a great chart but I can't remember where I saw it. I will try to remember. I'm old sorry. Over 100 they are basically dormant that's why they will rot so fast if your substrate holds lots of water.
I am using a liquid fertilizer (miracle grow) right now. I am old as well...I can remember reading something about heat and Osmocote just can not remember where. I have noticed a slow down in growth (my plants...not me personally)..I was assuming heat related just was not sure if I should continue fertilizing.
Once the soil temp goes over 40C (104 F) roots of many species begin to die. They are already stressed at 30C. Combine that with increasing salinity as the medium dries and you run into trouble. With controlled release ferts like osmocote, the rate of release goes up with increasing temps. Nutricote is better in this respect. If you cannot remove it, it's important to keep the moisture level high and flush often to keep the salinity as low as possible. Discontinue or drastically reduce fert rates with such high temps. Shade the pots or wrap in aluminium foil. Shade the whole plant 50% if possible. Tropical plants are more resistant that temperate species. Large pots heat up slower than small.
GrimLore
Bonsai Nut alumnus... we miss you
I normally use high concentrations of fertilizer during the growing season. We get a two week period mid to late Summer where the temperatures are far above normal. During that time I STOP the fertilizer and double up on the water. The plants/trees stall and won't use the fertilizer - they do however require more water as not to dry out.
Grimmy
Giga
Masterpiece
When you fertilize in the heat of summer your making the tree compete with the uptake of salts and water, hence fertilizer burn or worse. It's best not to fertilize in summer on just make sure they are watered well. As soon as growth slows or stalls is a good indicator that it's time to slow the ferts down
Lazylightningny
Masterpiece
Be careful with Osmocote. Above a certain temperature, they release huge doses of fertilizer- good way to burn roots (just ask me). I saw a chart in a study somewhere online; a google search should turn it up.
Paradox
Marine Bonsologist
I agree with the above posters. I stop fertilizer application when the growth slows down in July/August and start again when growth resumes.
M. Frary
Bonsai Godzilla
I keep on pouring it to them.
Same dose.
Same rate.
No problems with things burning.
Ever.
Same dose.
Same rate.
No problems with things burning.
Ever.
GrimLore
Bonsai Nut alumnus... we miss you
Actually I never tried that during that creepy hot spell so it but I have switched to highly organic the last couple of years and I am certain it would be either harmful or useless. As with everything mileage varies in potted culture
Grimmy
M. Frary
Bonsai Godzilla
It's supposed to be in the 90s here next week.
And I'll just keep on pouring it on.
And I'll just keep on pouring it on.
Paradox
Marine Bonsologist
A couple of days probably won't slow the plants down much if at all. As cold as its been, it might jump start them instead.
It's when they go into the longer term semi dormancy and aren't using the fertilizer that concerns me. IMO, Why pour it on if it will just wash out and do no good to the plant? Waste of fertilizer and $.
M. Frary
Bonsai Godzilla
Here my trees don't go into summer dormancy.
They just keep on going.
Like they know what's in store for them come November.
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