When to move container perennials to larger container

  • 14 Replies
  • 4506 Views
*

Tobiass

  • New Member
  • *
  • Location: Cambridgeshire
  • 12
I have a few young perennials in 4L pots which are in flower and active growth at the moment.  These are:
daylily, yellow storksbill, alstroemeria, potentilla arc-de-ciel, tangerine coneflower.

I bought them in March/April and at that time I planted them into a pot 1-2 inches larger than the original. So they are in 4L containers. It was suggested that I pot on them on slowly as required rather than straight into a very large pot

I realise that they are already starting to become root bound - I can see some visible presence of roots through the bottom drainage holes - however the roots are not coming out of drainage holes yet. I have read so many suggestions but I am still unclear when to repot in to a large container. Post-flowering in Autumn which will help protect roots over winter or next spring?

Thanks for any suggestions

*

mumofstig

  • Global Moderator
  • Hero Member
  • *****
  • Location: Kent
  • 53031
Re: When to move container perennials to larger container
« Reply #1 on: July 17, 2013, 07:29 »
I'd certainly pot them into final pots now before they suffer too much of a growth check.
Lesley x
I'm not good, I'm not bad - I'm just me, and sometimes I have to apologise for that ;)

*

Tobiass

  • New Member
  • *
  • Location: Cambridgeshire
  • 12
Re: When to move container perennials to larger container
« Reply #2 on: July 17, 2013, 18:06 »
Thanks for the reply mumofstig. As I a complete novice, forgive the simple questions
1. Whilst in active growth at the moment - foliage and flowering still going on - won't I disturb the rootball and cause the plant to become very unhappy?
2. If I do pot into a large container e.g. 7.5L now and its ok to do that when its in the growing season, should I move the containers to shady place for a few days so they don't get shocked??
3. Also it was suggested to me that putting in a final container (40cm diameter) fro 4L pot would plant look very small and mostly likely to cause root rot. I know that logically when you plant out in the garden then this shouldn't really be a worry? But it is likely that the plant will take 2-3 years to grow to a size to fill container????

Thanks

*

New shoot

  • Global Moderator
  • Hero Member
  • *****
  • Location: Reading
  • 16174
Re: When to move container perennials to larger container
« Reply #3 on: July 18, 2013, 18:00 »
Hi Tobiass

I'm assuming you want to keep these plants in containers long term and that is why you are moving to 7.5L pots.  If not, I would plant out into the garden now or it will be some big holes to dig  :)

The potting on in gentle increases is really relevant to small plants.  At 4L pots, your plants are established enough to cope with potting on into 7.5L now.  As long as you are careful and don't knock the roots around too much, they will barely notice the move.  It will give them a 3 months or so growing time for the roots to spread.

Root rot will only be an issue if the pots sit very wet - unlikely at the moment.  Just take care over the winter that you raise the pots off the ground with bricks or pot feet to ensure any excess water drains away  :)

*

Tobiass

  • New Member
  • *
  • Location: Cambridgeshire
  • 12
Re: When to move container perennials to larger container
« Reply #4 on: July 19, 2013, 00:10 »
Thank you very much - clarified things for me.
Yes I want to keep these in containers long-term outside of the front of the house/patio. So I will pot these on into 7.5L containers now and get some pot feet too.
All my other perennials have already been planted out in the garden and are doing fine so far.

*

Goosegirl

  • Hero Member
  • *****
  • Location: Caton, Lancaster.
  • 7229
Re: When to move container perennials to larger container
« Reply #5 on: July 22, 2013, 14:14 »
Unless your plants dislike root disturbance (which I don't think they do) I would recommend getting your larger pot filled with a bit of compost at the bottom, then tap your plant out of its original pot (having watered it well in the evening beforehand) and gently tease out any side and bottom roots that are compacted. Now insert the original pot into the new pot and adjust its height in the new pot with more compost if needed so its rim is about one inch below the new pot's rim, making sure you firm down the added compost well. Get handfuls of compost and fill the gap between the old and new pot, again firming down well down the sides. Gently ease out the old pot and put your plant in the hole. Add more compost as necessary to fill any gaps at the sides plus a bit on top, then water well with some added dilute seaweed feed or similar to get the roots going.
Spring always comes when we sow the seeds of life.

*

BobE

  • Hero Member
  • *****
  • Location: Near High Wycombe
  • 1590
Re: When to move container perennials to larger container
« Reply #6 on: July 23, 2013, 13:08 »
Unless your plants dislike root disturbance (which I don't think they do) I would recommend getting your larger pot filled with a bit of compost at the bottom, then tap your plant out of its original pot (having watered it well in the evening beforehand) and gently tease out any side and bottom roots that are compacted. Now insert the original pot into the new pot and adjust its height in the new pot with more compost if needed so its rim is about one inch below the new pot's rim, making sure you firm down the added compost well. Get handfuls of compost and fill the gap between the old and new pot, again firming down well down the sides. Gently ease out the old pot and put your plant in the hole. Add more compost as necessary to fill any gaps at the sides plus a bit on top, then water well with some added dilute seaweed feed or similar to get the roots going.


At these sizes Id not pot on into compost alone, compost is a short term feed for plants that will be moved on.  I would put them into JI no 3.  This is a soil based mix designed for mature plants.
« Last Edit: July 23, 2013, 13:09 by BobE »

*

New shoot

  • Global Moderator
  • Hero Member
  • *****
  • Location: Reading
  • 16174
Re: When to move container perennials to larger container
« Reply #7 on: July 23, 2013, 14:11 »
At these sizes Id not pot on into compost alone, compost is a short term feed for plants that will be moved on.  I would put them into JI no 3.  This is a soil based mix designed for mature plants.

Compost is a potting medium, not a feed.  Multi-purpose compost generally has feed in it to last around 6 weeks and will break down into a dust-like texture in a pot eventually.  Some people still prefer to plant perennial plants into it as it is light and the pots are then easier to move.

JI no 3 is also a compost, but is soil based as you say.  It is therefore more stable in texture in the long term, but makes a pot very heavy to move.  It also has some feed in it, but again, only designed to feed for few weeks  :)

*

BobE

  • Hero Member
  • *****
  • Location: Near High Wycombe
  • 1590
Re: When to move container perennials to larger container
« Reply #8 on: July 23, 2013, 14:13 »
So NS, are you suggesting using garden soil or a mix theroff.

*

New shoot

  • Global Moderator
  • Hero Member
  • *****
  • Location: Reading
  • 16174
Re: When to move container perennials to larger container
« Reply #9 on: July 23, 2013, 14:15 »
So NS, are you suggesting using garden soil or a mix theroff.

Where did I mention garden soil  ???

I've given descriptions of two types of bagged compost and the pros and cons of each  :)

*

BobE

  • Hero Member
  • *****
  • Location: Near High Wycombe
  • 1590
Re: When to move container perennials to larger container
« Reply #10 on: July 23, 2013, 14:19 »
We were advising on taking mature plants from 4 to 7 litre pots.  I don't think a compost mix is long term enough for that so its either JI3 or garden soil. (With a bit of BFB)

*

New shoot

  • Global Moderator
  • Hero Member
  • *****
  • Location: Reading
  • 16174
Re: When to move container perennials to larger container
« Reply #11 on: July 23, 2013, 14:28 »
We were advising on taking mature plants from 4 to 7 litre pots.  I don't think a compost mix is long term enough for that so its either JI3 or garden soil. (With a bit of BFB)

JI no 3 is a compost mix.  Its soil mixed with other things.  It differs from multi-purpose, but the OP could use either.  It would work.  The plant would just need repotting more often as the compost texture broke down, but a perennial is going to fill a 7.5L pot and need that anyway every couple of years.

I think advising using garden soil is risky.  You don't know what type of soil the OP has - could be really sandy or heavy clay, which would not be good news in a pot  :)

*

BobE

  • Hero Member
  • *****
  • Location: Near High Wycombe
  • 1590
Re: When to move container perennials to larger container
« Reply #12 on: July 23, 2013, 14:31 »
Good point about the soil.  So it looks like a repotting operation every couple of years then.

*

Goosegirl

  • Hero Member
  • *****
  • Location: Caton, Lancaster.
  • 7229
Re: When to move container perennials to larger container
« Reply #13 on: July 24, 2013, 14:50 »
Just looked at your original post, Tobiass, and see that it was more the timing than anything else. As long as you keep them well-watered after potting, you can do it at any time now. As for the potting medium, in my post I just said compost, but not which sort - i.e. multi-purpose or soil-based, which has led to a further discussion. IMHO, if you want them to be permanent pot plants, I would mix multi-purpose with soil-based John Innes No 3 (one part MP to two JI) to give you a suitable medium that provides drainage (place small pieces of broken terracotta, small stones or small bits of polystyrene over the bottom the pot beforehand) plus will still retain water in the summer rather than multi alone which can dry out more quickly. Yes - they both have a limited amount of feed, but you can let them use it up now until autumn when they won't need it, then start next spring with either a water- or granule-based feed with a bias towards potassium (Tomorite, hanging-basket feed etc).

*

BobE

  • Hero Member
  • *****
  • Location: Near High Wycombe
  • 1590
Re: When to move container perennials to larger container
« Reply #14 on: July 24, 2013, 15:02 »
Sounds good.



xx
Container hellebores

Started by DIGGER on General Gardening

1 Replies
1494 Views
Last post January 08, 2009, 23:58
by Trillium
xx
climber for container

Started by andyf75 on General Gardening

2 Replies
1596 Views
Last post June 13, 2016, 09:53
by andyf75
xx
More Container Advice Please

Started by mrs bouquet on General Gardening

3 Replies
471 Views
Last post November 01, 2020, 14:41
by mrs bouquet
xx
Container Roses

Started by aec on General Gardening

1 Replies
1587 Views
Last post June 20, 2010, 19:31
by DavidT
 

Page created in 0.098 seconds with 32 queries.

Powered by SMFPacks Social Login Mod
Powered by SMFPacks SEO Pro Mod |