Backyard Aquaponics
A place to discuss aquaponics

not strickly AP related but it could well apply:
whats the least back breaking way of repotting a large pot plant?

i have an avocado tree in a large pot 80cm across and it's flowering this season, which will likely mean fruit and the need to replenish the potting mix next year. given there is about 60kg of soil in that pot i'm not looking forward to the task.
i'm thinking of just getting in there with the spade and hacking out the soil from the edges and dumping pure compost in there to top it up. it'll take out some of the root zone and the soil at the same time, shouldn't stress the tree as much as if i removed the whole thing from the pot.

Timmy

If you arn't going to repot it you could get away with drilling holes round the outside edge of the pot and filling those with new compost. Take a few leafs off, just remember tops and bottoms should be balanced.

i think i might get away with scraping away the top layer this year we'll see how much it fruits, next year definitely it'll need replenishing.

I've got a few larger plants and trees in pots and all I do is top up the soil. Liquid and dry fert every now and then. At some stage I'll have to re-pot but not for a few more years.

are they hungry tree's like citrus and avocado though?

avocado, orange, mango, apricot and an elephants ear. Also some prehistoric looking thing with spikes but its only new. The picture is a apricot that is still young. The gravel is only on the top. Dirt and fert mix with mulch.

i've seen most recommendations to prune the root ball once every 2 years once the tree reaches it's desired size, and to replenish the soil once a year even if it's a layer on top.

Wonder why they want the roots pruned. I try to leave the roots untill they get root bound in the pot. And then its only if the plant is not producing properly. Some plants don't grow well until they become bound. As long as you can get the new topsoil and fert moving throughout the root zone by top watering every now and then. I might have to do a comparison next time I get a new tree. An excuse to get 2 instead of 1.

Its because you are effectively trying to bonsai the tree. You should prune the tap or larger roots to encourage fine laterals. And as I said before prune the tops and bottoms. Eventually the fine laterals take up all the space in the pot, which is why you have to trim some off.
If its going in the ground you should be going to larger pots .

One thing that might help is to try vermicomposting. Simply add some worms and some organic material for them to eat periodically and cover with newspaper. In effect you are adding more compost on a consistent basis and the casings provide excellent nourishment for the tree.

Neat idea DT , wouldn't work in a small pot but at this size they would also clear out the dead roots and provide aeration.

I am a believer. I have a worm box and it is doing well. The casings are excellent for starting seedlings and then putting the plants in the grow beds

there are lots of worms in all my pots but i never really considered actively encouraging it in that way. i do throw on worm castings from my worm farm but i might try an experiment with it.
anyone in perth have a good source for large terracota or glazed pots ? needs to be 80cm or larger and dirt cheap