When to repot

[matt pounds]

I bought a dozen different marginal plants/grasses a couple of weeks ago, which came in 1L mesh plant pots. In all cases the plants are looking healthy and the roots have pushed through the mesh by 5cm+. Should I ignore, trim the roots or repot?
Many thanks

6,000 litre brand new brick/fibreglass pond, filtered, 40 goldfish, assorted plants

 

[zozo]

If they are in a mesh pot, than repotting aint a nessecity, the roots can go where they want anyway. If you see deficiencies it is alway possible to fertilze the water or put clay cones/sticks in the pot between the roots. Depending on the deficiency it has. It also kinda depends on the plants sp. Some do very good with feeding of the water column, other heavier feeders like rich muddy soils.. If these soils wear out it should be (partialy) replaced. Nymphaea is such a plant doing best on a rich muddy soil, some types of grasses prefer this also. Personaly i like to use inert substrates for the sp. that grow fast feeding from the water column and mix in a bit of clay soil for the ones who need it, like nymphaeas. Nymph can grow on inert substrates but it will be significantly slower and smaller. Using only organic pond soils for all plants, can cause a rather heavy load on the water column, what the plant yet doesn't use leaches out and can cause algae blooms like green water. A reason why a lot of people think they have to run to the LFS for a UV light in the filter. 😉

These are things you need to find out by experimentation and experience, what grows best on what. Personaly i like to avoid to much plant sp. prefering heavy content soils.. According to most pond shops all need it for convinience but that's not true..

But mesh pots you do not realy need to remove, if the plant gets to big and or you need to weight the plant down, trim a bit of the roots, take a bigger mesh pot put in the plant with pot and all in with some stones and substrate and put in back in the pond. You could cut the old mesh pot off, but this is actualy unnessecary extra work and mess. 🙂 A mesh pot aint a restriction for the plant. Only closed non meshed pots, in there roots will coil up and sufacate itself, becaus eit has no where esle to go.

 

[matt pounds]

Thanks Marcel
A really useful reply, made a lot of sense
My Nymphaea (I've gone for Gonnere) came in a 3L so that should be fine for a while as you've gathered I'm new to pond gardening so I will take your advice, leave alone and monitor for the time being whilst my experience grows
Appreciate you taking time out to answer
Cheers

 

[zozo]

My Nymphaea (I've gone for Gonnere) came in a 3L so that should be fine for a while

Depending on the kind of lily, tuber type, if it's a small/medium one it can do rather long in 3 litre. Most lilies i've seen are tuberosa or odorata which grow sideways.. So do not need deep pots but rather need a wider pot. I use these larger square +/- 20x20x20 cm - 8 litre mesh pots and cut the hieght, make a shallow plate from the pots bottom about 5cm high or even less if its a very small lily.. Fill it with a heavy clay soil and top it off with medium sized silica pebbles for the weight. It can do a few years like this and if needed very easy to replace the clay soil. Than the tuber has room to grow sideways and the roots will spread over the bottom of the pond. You will always have debri accumulating on the ponds bottom, the lily will feed on that too... For me this works very good.. And meshed pots are very easy to cut with sciccors. But how good this works also depends on the depth the plant is placed, the lower the plate the harder to reach if placed to deep.

In shallow ponds this also looks much beter, than such a 20 cm high pot filled with to much (8 litre) clay only leaching unnecessary into the water column. win win, keeps the water clear, so you see the bottom but do not see such a big ugly 20 cm high pot. 🙂 Which would actualy make a 50 cm deep pond half as deep if filled to the top.