Our new raised bulb bed

[Paul Cumbleton]

Since we moved to Somerset 3 years ago, Colin has been wanting to build a raised bed in which he wants particularly to experiment with growing a range of Fritillaria outside (his collection at present being totally in pots in a glasshouse). We will also plant a range of other bulbs, including experimenting with some of my South African bulbs to see if any prove growable outside in this climate. Easier, common bulbs will also be included to ensure we have at least something beautiful to enjoy if all the experimental ones fail!

This past few weeks at last saw this project started. We had some stone left over from the building of the crevice garden so it made sense to use this, to both save money and to make things match. First picture below shows the area (previously grass) with a small trench dug to delineate the bed. Picture 2 shows part way through building the low wall and picture 3 once the wall was complete. You will see that at the rear we have used concrete blocks - being at the back they will not be seen and they are capped with stone to match the rest of the wall. Once filled with growing medium they will not be at all visible.

Paul

[bibliofloris]

Looks beautiful, Paul — I bet you’ll both have fun with that! I’m assuming you’re thinking about wet summer South African bulbs?

Seattle is 8b as well, though obviously much drier in summer, and many of the eucomis and hesperantha grow reliably in the ground here (with a little mulch for some of the eucomis, and a lot of watering in summer.) I’ve been meaning to find out what grows with them in the wild, so will follow your experiments with interest!

Kelly

[Paul Cumbleton]

I’m assuming you’re thinking about wet summer South African bulbs?

Hi Kelly,
Actually no, I'm going to try some of the winter-rainfall bulbs. While the hardiness or otherwise of the summer-rainfall plants from South Africa is fairly well known over here, the winter-growing ones are largely un-tested. Even if some prove hardy, summer moisture could be a problem. But we don't know if we don't try, so it will be fun to find out.

More to follow on this project soon.

Paul

[Graeme]

Looks fantastic - I would kill for stone that square to build with..........

[Leucogenes]

A fantastic job... Paul.
Must be exhausting...at the current temperatures.

Thomas

[fermi de Sousa]

Hi Paul and Colin,
That's a raised bed on a grand scale - I'm sure you'll have enough plants to fill it too!
I found last year that some South African bulbs which had survived in pots in previous winters were badly affected (some were killed outright) by the drop to -7 ^oC in July when we were away and unable to protect them. Hopefully in the ground yours will tolerate lower temperatures,
cheers
fermi

[colin e]

Paul described the initial construction of our new raised bulb bed. Having built it, one thing I did want to do was to dig over the ground to break it up (picture 1). I thought it would be a relatively quick job, but it ended up being a more serious job!  You can see why by viewing what came out from one end of the bed (picture 2). I think the previous owners had been putting waste mortar/cement from building work here. There was only about 5cm of soil above this so it would have done a good job at hindering drainage.  Having removed this, a layer of sharp sand approximately 6cm deep was spread over the bed and then dug in. The idea behind this was to try and limit any barrier effect between the bulb bed mix and ground soil.

[Maggi Young]

Crikey!  A classic case of previous owners "sweeping" their junk "under the carpet" ! 

[colin e]

Next job was to fill the bed with a growing medium. Well deciding what to use did cause us quite a headache. Simply put, any mix has good points and bad points. Plus this is our first bulb bed. Of cause Paul does have the experience of the sand beds plus the crevice garden at Wisley and our own crevice garden here. My basic Fritillaria mix would have just been too expensive and I do not think it would have worked in a bed. To cut a long protracted story short, we ended up using what is sometimes called ‘dirty sand’. Our mix was made up of 20% loam (picture 1), 40% horticultural sand (picture 2) and 40% gravel (2-6mm) (picture 3).

[colin e]

Orders were placed and 6 bulk bags turned up. We ordered a spare bag of gravel. So then came the mixing and all I can say is cement mixers are a life-saver (picture 1) and ours does get used a lot! One thing we forgot to take into account was when you put 60 litres by volume in, you do not get 60 litres of mix out. How? Simple when you think about it - the 40% of gravel creates a lot of air spaces that sand and loam can fall into. So I ran out of loam first. The horticultural sand bags were about 20% bigger than the loam and gravel bags. So after running out of loam I finished off the sand doing a mix of 60% sand to 40% grit mix. This used up most of the spare bag of gravel! I also put a layer of my waste Fritillaria mix after repotting about 13-15 cm from the top (picture 2). The reason for doing this is 50% of that mix is moler clay cat litter, so should hold onto nutrients for the bulbs. The 20% loam was meant to do this but it had a high sand content, so its nutrient holding ability probably will not be that good. Just two more pictures, (picture 3) is me levelling out the mix as I went along and (picture 4) the filled bed with Paul in the background. Now there remains only the top dressing to apply and bulbs to be planted.

[ashley]

Great work Colin and Paul  
Will you allow for settling, or plan to protect from winter rain?

[David Nicholson]

Smashing job.

[ArnoldT]

Paul:

Looks like one guys doing all the work.

[sokol]

That looks quite exciting to me. Lacking a greenhouse I have to plant all bulbs out, but mainly in protected frames. I am curious about the results.

[colin e]

Hi Ashley,
As to settling, when I was filling it Paul was going round with a shovel pushing the shovel blade in and out of the mix to help settle it a bit. But settling was another issue that we had long discussions about because we did not want to compact the mix and cause drainage problems. Winter wet combined with any freezing we get will probably be what kills some of the bulbs put in. So we are expecting to have to add more in the future and deal with any arising issues.
The idea of the bed is to see what we can get to grow outside and unprotected here, so we don’t plan to cover it for winter.

Colin