Pot bound roses - root pruning
Hi everyone - but with a special call out to our rose guru @Marlorena....
I have offered to help a friend who has 2 small shrub roses (I think they're 4 - 5 yr old DA's but labels are long since lost) in terracotta pots which are a bit too small for them. However, the pots were expensive and she won't change them.
The roses were repotted very badly by her non-gardening son-in-law about 3 years ago leaving the graft union 2-3" above the level of the soil and the top 1-2" of roots completely exposed. Apparently there is a large root mass which is why the plants sit so high in the pot.
Can I do some severe root pruning on these roses and which roots can I tackle?
Is it OK to cut the tap root if that's too long? By how much?
I understand it might be ok to cut some of the side anchor roots. Can they be reduced by about half if necessary?
And what about the fibrous feeders? Can I just trim those to fit in the pot?
I was going to reduce the top growth of the roses by between a third and a half depending how much I need to trim the roots. Is this the right thing to do?
They are currently potted in pure MPC but I was planning to repot using a mix of one third MPC and two thirds John Innes No 3. Does that sound right?
I will water them in now and was going to suggest a regular feeding routine starting in March. 'Proper' rose food for the first feed then liquid seaweed once a month after that. Any views?
TBH - if these were my roses I'd just get on and do it but they're not. She's quite emotional about these plants and is putting all her trust in me to sort them out. It feels like quite a responsibility!
I'd really appreciate your inputs regarding my plans and whether there's a better way to go about things.