I have been irrigating my BB fabric pots simply by soil drenching at least twice a week. Each time with a sufficient water amount so that run off is around 20 percent. The branch tip as well as the shriveled leaves shown below suggest water stress right?
I just could establish the drip line irrigation newly and use next week… I can imagine that soil drenching might not be the optimum irrigation method but what I have observed is that the drainage is extremely high. Within seconds you see the runoff…
Do you think it is normal?
My substrate is made up of peat moss, pine bark, pumice, a bit perlite and coco peat.
I will integrate a timer and irrigate every day and fertigate once a week.
I would like to ask wouldnt it be better to increase water holding capacity rather than irrigating too frequently… Both with regard to nutrient leaching as well as high water consumption.
I know frequent irrigation is better for leaching of salts but still I would like to ask how can one increase water holding capacity in pots and what would be your opinion on this issue generally.
Use DE perlite sized, holds more water than pumice. Make sure pots are light in color or put foil on them. Mulch really thick. Put saucers underneath to keep run off
One thing that you should be aware of is peat moss and pine bark become hydrophobic when they dry out and will not easily absorb any water. Commercial potting mixes contain wetting agents to prevent that from happening, but when it does the water will just run though, or down the sides of the container if it has shrunk without absorbing into the mix.
I find that watering lightly once and then heavily about 10 minutes later will often allow the mix to become wet, you should judge how much water is being absorbed by the weight of the container to decide if it is working. There are alcohol and petroleum based wetting agents, and natural ones like agar and aloe. You can also make your own by fermenting plants that contain saponins, such as lettuce.
What do you guys think about mixing coco coir with the peat moss to aid with water retention? Coco coir loves sucking up water and would probably keep the peat moss moist.
it would but it would also raise ph. try like Drew said. that large DE holds a lot of water and 2- 3in. of mulch on top keeps the soil moist a lot longer and distributes the water more evenly. the DE is called floor dry at napa. true value i guess carries it also.
5.5 is ideal so neutral is 15 times more basic than ideal. I don’t think it is enough to raise it to neutral but you are pulling it probably in the 6.0 range. Blueberries should grow there too, just not as good. Coir is a replacement for peat, but I’m not sure it is superior? You might be better off using more peat instead.
What are you using? Burned tips also can be from fertilizer, or a too acidic environment.
The idea I was putting forth was not to use coir as a replacement for peat, but as an additive to mitigate peat’s tendency to become hydrophobic as it dries out. So say 5 - 10% of the mix could be coir to wick water into the mix even if it dries out. I don’t think that amount would have a drastic effect on the ph.
First of all I d like to thank you all for the feedbacks.
I’ll use DE next time and am planning to use saucers as well… I had already doubled the pine needle mulch a couple of weeks ago.
I ll increase the ratio of cocopeat to a certain degree as well.
Drew, for some reasons I just could only irrigate them until now with a pH adjusted water of having a pH value around 4.5-5.2… I have not yet used any fertilizer. But a couple of times I added sulphiric acid more than necessary and irrigated with a pH value around 3.8-4.0
But this was for sure not more than 5 times.
I ll start fertigation next week…
Any tactical suggestions to minimize nutrient leaching? I mean these days the plant needs to be irrigated everyday due to hot weather. How about 1 or 2 days minimum irrigation without run off after the fertigation day? (by fertigating once per week).
I don’t either, and it would probably help. If the peat is getting dry enough to become hydrophobic though the person is not watering enough.
Use Holly-Tone. It is my main fertilizer for blueberries. Be careful not to get the potting mix too acidic too. It’s easy to do in pots. I know I killed a couple that way. As long as your potting mix is fairly acidic (and yours is!) sulfuric acid is not needed. This may have caused the burned tips, very possible. One really has to monitor soil pH. When I killed a couple the pH of the soil was 3.0. I like to use urea for fertilizer when pH is right so I would use Miracle Grow for acid plants. If pH was a little high I would use Jacks acid fertilizer which has ammonium sulfate. Once a month I give them soluble, and also add Holly-Tone. Holly-Tone takes 2 weeks to work, and kicks in as the soluble runs out .
When the soil pH goes south of 4.5 I start watering with tap water. This brings it up. I usually use rainwater. I no longer use sulfuric acid. But if I’m out of rainwater for long periods, I will use it. A few waterings with tap won’t hurt. But anymore I go to the acid.
It all depends on the current pH of the soil.
Soon I will have blueberries, some are starting to turn blue!
I’ve read that you shouldn’t ever let blueberry roots get dry, and I’ve seen the results of this in some of my 5 gal containerized blueberry plants. The leave edges get brown and crumbly and eventually fall off. Fortunately the plants always come back when they get watered adequately.
In the hot long summers here (zip 90290) for container plants (and fruit trees) that suck up water, I have Sterlite dishpans (12 qt and 18 qt) that 5 gal and 15 gal containers will fit in. I put the water sucking containerized plants in these dishpans (which have 5-6" sides) and add as much water as I think is needed. I also water the plant from the top. As the plant uses up the water in it’s mix, it’ll suck up water from the dishpan. Usually the dishpan will be almost dry within a week, sometimes sooner, so the plant roots aren’t sitting in water for too long.
If you have a Walmart in your area, these dishpans are very cheap(1.88-3.00) and I’ve accumulated a bunch of them(mostly white ones) in recent years. As each summer gets hotter(and plants/trees start wilting on me more often) I will use more and more of them and when the weather cools off I remove them until the next hot summer. I haven’t started using them yet this year as the early summer days have been cool.
These are much better than saucers, they are durable, don’t tip over easily, and hold much more water. I use them for blueberries, blackberries, gogi berries, citrus, apples, corn, buddleia, hyssop…plants that are sensitive to going dry and wilt quickly.
I am working with some sandy river bottom topsoil filling in a flower bed today…
if I had some blueberries to pot…this would be ideal soil. About 6.5 pH might need lowering a little.
Jumping in randomly here, but in my experience, coir doesn’t really prevent peat or bark from becoming hydrophobic until it makes up about 60% of the mix by volume.
