Topping up large container

The perlite for drainage, right? I think I added a decent amount of grit to my mix for that purpose too

 

I wouldn't use Perlite for a big container @latimer , especially for something like a bamboo. Expensive!
I'd only use that for small pots with young plants or seeds/cuttings. Grit or even just pea gravel mixed through it all will be fine for drainage.

 

I've only ever used perlite in mixes for houseplants, of which I now grow few as they are unreliable .

For your bamboo @latimer, a soil based JI3 compost will be adequate. Other plants may like added MPC or grit to lighten the soil or aid drainage. I mix up all sorts of blends, depending on the plant and the time I plan to keep it in a container. Another point to add is that some plants actually like being pot bound and perform better! (Bamboo is not one of them!)

 

Hi @fairygirl good to see you!

Yeah, usually I do just use grit. I’ve got a bag of perlite and vermiculite and can never remember the difference and what does what! lol

 

Soil mixes are beyond my level of expertise at the moment @Plantminded !

 

Good to 'see' you too @latimer
Don't worry too much about the exact mix - long term planting, especially of anything shrubby or woody, needs soil to thrive, because compost disappears - hence the drop in your container too.
They still need adequate drainage too, hence the grit or gravel.

Adding a bit of commercial compost will add a bit of extra nourishment, but it isn't really vital, other than to give that boost. Most shrubs are fine with just soil alone. You can also get those J. Innes mixes in GCs, which are tailored for various types of plants - some have ericaceous compost in them for plants which like that. J. Innes is really just a formula.
Perlite and Vermiculite basically do the same job, and help with drainage, but the latter is heavier, so it's good for topping pots/trays with seeds, whereas Perlite is lighter, so it can blow away more easily. Many people have a personal favourite though. It's often said that Verm. holds more moisture, but I don't know if that's true.

 

My container grown boos get the lot thrown in there. Homemade compost, old mpc, grass cuttings, chicken pellets, blood snot and guts and anything else I need to 'lose' around the garden. I stopped using decorative stone just because when the level drops, it's a PITA to get all the stones out to top up!
Actually, my big fern pots get the same treatment

 

Lots of web information on perlite vs vermiculite, and likely grit. Vermiculite is definitely more water retaining and from my limited experience makes the mixture heavy. Water is not a problem most of the time for where we live, weight of the mixture and pots are. As for cost £30 for 100L but a bag lasts us 1-2 years.... Grit is cold and heavy in my experience, with the former in this country being an important factor. Interestingly neither vermiculite nor perlite were known by many Italians, but used for growing young plants by commercial growers (most were perhaps Romanian) . Certainly vermiculite would have been useful there as the soil was super heavy and rock hard in summer.

 

It’s not a precise science @latimer. Many people have their own preferences as you will see from the other replies but the main point is that container grown plants need more attention than those grown in the ground and are dependent on the gardener for food and water.

 

I like that recipe @flounder! I’m interested to know what bamboos you grow and how long you’ve had them in containers. I grow mine in the ground as the only time I had some in pots they were continually dropping leaves and looked unwell.

 

Thanks @fairygirl @DiggersJo @flounder and @Plantminded

Lots of great information there!

Regarding the other container, here’s a few pictures. I’m guessing that with a good water they should be ok being replanted.

 

There looks like a good root depth there so I don’t think you’ll need to replant them @latimer, unless you want them higher up in the planter. I normally remove all the previous year’s fronds off both evergreen and deciduous ferns just to tidy them up and give the new fronds space to unfurl. Your grass or sedge just needs the brown leaves snipping off. You could feed them also with a liquid feed or a small amount of BF&B but not essential for those plants. I’ve just noticed your Acer, is it in a pot on top of the compost/soil in your planter? The pot looks a little small for it so a slightly larger one would be better, using soil based compost.

 

@Plantminded actually, it's only got soil to about half the depth, I filled the bottom with blocks to save having to fill the whole thing with soil.

I'll definitely give the grass a tidy up, also the ferns. I didn't know the evergreens needed trimming back too.

The acer is in a pot, sunk down into the soil in the larger container. I'll pop in out and see how the roots are but last year they weren't really filling the pot much so I decided not to pot it on.

 

I only tidy up the evergreen ferns @latimer, not all evergreens! It’s not essential to tidy the evergreen ferns, I just prefer the fresh colour of the new year’s fronds! You can reshape the ivy if you want to though. From your description your planter does need replenishing, again using a soil based compost.

 

Haha, don't worry @Plantminded I understood that, I wasn't about to trim every plant in the garden to the ground!

I shall have a go at replenishing. I might actually plant one or 2 of the ferns elsewhere, I want to get a bit more colour in there and a different type of leaf. I've tried heucheras but they all seem to get eaten by the vine weevils!