Bulb frame

[Darren]

I looked for a thread about bulb frames but was surprisingly unsuccessful. I find mine works really well so I'm going to show some pics! And hope you will do likewise if you grow in frames.

The frame is basically a big raised bed made from tanalised timber. On top I constructed a frame to support sheets of polycarbonate on the top during summer and during winter. The frame is open to the sides (meshed to keep out beasties) all year round. The top comes off from early March until late May, then again from early September until November.

The response of many frits, tulips and aril Iris to frame culture has been amazing. There are also lots of Crocus, Sternbergia and Cyclamens graecum and mirabile, assorted Corydalis, Anemone, Ornithogalum, Muscari and Bellevalia, Acis. Even Tropaeolum tricolor and Ranunculus asiaticus have survived the last two winters.  

The first pic shows the frame with the cover in place - I removed it this morning until summer - see second pic. Some taller frits were starting to touch the cover and would have been deformed if I'd left it longer.

The next couple of pics show the scene last autumn with Cyclamen graecum, Sternbergia sicula and leaves developing on onco Iris. The last pic is a preview of what is to come - Fritillaria davisii taken in this frame last spring (I struggle to flower this in a pot but it does great out here!) . I will post more pictures as things flower.

[Maggi Young]

Wow, Darren, thanks for starting this thread..... surely there will be plenty inspired by the sight of your very productive frames? 

[ArnoldT]

Darren:

Thanks, great looking.

Are the bulbs potted or growing freely in the ground.

[Darren]

Thanks to you both. 

Arnold - they are technically growing in the ground but are separated into groupings by putting the bulbs in plastic baskets. Soil is basically a layer of old bulb potting compost from bulb repotting, over a layer of rubble for drainage. Exceptions are - some Crocus which are plunged in small pots to keep them identifiable, separate and to make them easy to remove if I feel they are 'going back' and could do with fresh compost around them. They root out through the bottom of the pots and seem to like the extra root run and the coolness resulting from being grown in the frame. Also the big Corydails integra is now in a pot for the moment. It used to be grown just planted in the frame but I put the tubers in a pot last time I refreshed the frame in summer 2009 as I thought they might make a good show exhibit the following spring. I was right - see the Northumberland Show 2010 thread    Same story with one of the Cyclamen graecum (which I exhibited successfully at the Discussion Weekend in 2009). Both will be returned to the open soil at the next rebuild of the frame - probably 2012.

I do need to be careful not to plant anything that flowers early at the end of the frame nearest the fence as this end is in the shadow of the fence until about April so early flowering plants would easily etiolate.

[Brian Ellis]

What an interesting thread Darren, good idea.  What depth of 'top soil' have you over the rubble?

[ChrisB]

Most interesting Darren.  Do you reckon you will have to replace the compost or do you plan to just add fertilizer to it?

[Darren]

Hi,

I estimate there is about 25cm of soil above the rubble. I do dig the whole thing out down to rubble level about every 3rd year and replace the soil with the 'waste' from the bulb repotting. This is interesting in itself as I am always surprised by things that I have thought tender that occasionally appear in this frame as 'strays' and then do perfectly well or even better than they did in pots. The fact that the soil has been used in pots already and is (theoretically) exhausted has never caused any problems - the free root run makes up for it.

I add a scatter of Growmore around now when things are getting going, and then a scatter of potash in April.

One word of warning - never plant Arums in a bulb frame unless it is very big or you aim for a monoculture - they like the conditions TOO much...  Mine were evicted at the last emptying.

[Gerry Webster]

The soil in my bulb frame (like Darren's, used bulb potting compost) has remained untouched for at least 12 years, though I do feed quite heavily when plants are in growth. Sternbergias do very well, some crocus less well. Reticulate Iris thrive; too much so - they have now been removed.  There are lots of seedlings & strays from the used potting compost which one of these days I might get around to doing something about.

[David Nicholson]

I'm impressed Darren! Do you have any details on timber sizes used?

[ChrisB]

Gerry, when you say you feed regularly, do you use granulated feed or liquid?  I've got a bulb bed out in the open that I planted last autumn, so I'm asking because I've been wondering what to do about feeding.  Its gravel covered and raised so will behave much like the bulb frame in many respects.

[Gerry Webster]

Gerry, when you say you feed regularly, do you use granulated feed or liquid?  I've got a bulb bed out in the open that I planted last autumn, so I'm asking because I've been wondering what to do about feeding.  Its gravel covered and raised so will behave much like the bulb frame in many respects.

Chris - I have used pelleted fertiliser (Vitax Q4) but mostly I use liquid feed, weekly at half strength. In the past I have used Phostrogen or Tomorite, now I use Chempak no.3. I don't think it makes much difference - all have a fairly high potash content.

[Darren]

Cor Gerry - Reticulate Iris thrive? I must try that as I can't grow them out in the garden no matter where I try them. I could live with them being weeds in the frame 

David - I could measure up but the bases were not built by me. I just constructed the frame arrangement on the top. Susan had them constructed by a local garden building/furniture maker in 2004 to our outer dimensions. They are basically larger adapted versions of the big troughs they sell to local councils for bedding displays in town centres.

[jshields]

I'd be interested in seeing the compositions of the fertilizers that folks use.  I think the N-P-K values in the USA are calculated in some less straight-forward way than in the EU, but they still would give me a rough idea.  I am partial to soluble fertilizers, particularly N-P-K 20-10-20 (in the U.S. system) with micronutrients.  The stuff I use is called "Jack's Professional Peatlite" but I use it for everything, especially bulbs grown in my gritty bulb mix.  This probably approximates the used potting mixtures mentioned above.

[David Nicholson]

David - I could measure up but the bases were not built by me. I just constructed the frame arrangement on the top. Susan had them constructed by a local garden building/furniture maker in 2004 to our outer dimensions. They are basically larger adapted versions of the big troughs they sell to local councils for bedding displays in town centres.

Darren, I'm just interested in the timber you used for the top frame arrangement.

[Gerry Webster]

I'd be interested in seeing the compositions of the fertilizers that folks use.  I think the N-P-K values in the USA are calculated in some less straight-forward way than in the EU, but they still would give me a rough idea.  I am partial to soluble fertilizers, particularly N-P-K 20-10-20 (in the U.S. system) with micronutrients.  The stuff I use is called "Jack's Professional Peatlite" but I use it for everything, especially bulbs grown in my gritty bulb mix.  This probably approximates the used potting mixtures mentioned above.

Jim - I posted on the composition of some fertilisers available in the UK here:

http://www.srgc.org.uk/smf/index.php?topic=1967.15