Should I leave extra space between plants for bulbs?

curious_monk

Hi,

My first post, but have been lurking in the forum for a while!

I'm planning a garden at the moment, mostly perennials (e.g Salvias, Astrantias, Sedums, Asters and Hostas), ornamental grasses (e.g. Sesleria autumnalis, Molinia Moorhexe, Hakonechloa macra 'aureola') and ferns (e.g. Adiantum pedatum).

I'm planning to order and plant in the next few weeks. This follows a year of soil preparation, edging, fixing walls, making stepping stones, etc - and reading online and books!  

I'm also planning to plant a bunch of bulbs in the autumn:
- summer-flowering allium bulbs (e.g. Allium Cristophii, Allium Sphaerocephalon).
- spring-flowering bulbs (e.g Nectaroscordum siculum, Tulip Clusiana Lady Jane)

Do bulbs like these need much extra "space"?  

Specifically if I am going to plant them in between perennial plants/grasses, do I need to leave extra space between the plants/grasses for the bulb? 

I'm planning on using the fairly high densities recommended per plant in "Planting a New Perspective" by Piet Oudolf and Noel Kingsbury, which is of course different per species, but works out at about 8 plants per sq m on average. Also I will be planting mostly small plants, e.g. in 0.5l pots.

I have been assuming that the bulbs don't need much space and can just "squeeze" in between the other plants - helped by fact they generally come up earlier in the season before the perennials are in full swing.  

But would appreciate your collective wisdom on this!

Many thanks in advance...

Loxley

Generally you can overlap and treat the two plantings like overlapping layers, especially small things in late winter/early spring, but things can get more complicated when you have early appearing perennials and late appearing bulbs. Some alliums have pretty hefty clumps of foliage so you need to bear that in mind, for example.

Loxley

It would be worth having a look at Katy Merrington's instagram feed, she's looking after the Hepworth Wakefield garden and has posted images of the planting throughout the last year or so. It's excellent for seasonal succession. There's a plant list here.

curious_monk

Thanks very much @Loxley.  That's an amazing plant list!  
So, sounds like for a larger allium, would be worth allowing a bit of extra space for it...  I'll bear that in mind.