Bulb Frames

[Rimmer de Vries]

Bulb frames are often mentioned to successfully grow most of the Mediterranean bulbs or bulbs witch require dry summers or reduced moisture than typically available in one's local area.  However, we rarely see photos of the bulb frames forum member use.  Ads for wonderful commercial made bulb frames are often listed in the back of the SRGC and AGS journals but here in USA bulb frame are not available commercially so bulb frames have to be home made.

I am starting this topic to encourage forum members to post pictures of their bulb frames, both home made and commercial designs.

To start I show my two frames located on the south corner of my small residential house in a small town in southeast Michigan, USA (near Detroit) where the summers are hot and dry with periods of high humidity and monsoon rains and the winters are very cold and wet. The ground is frozen solid from about Christmas to March. Snow cover is irregular and can be deep or bare ground.

The shallow frame is made from stock treated 2" x 12" lumber with a diagonally cut 2"x6" board added for height it the back.  The cover is made from 2" x 2" cedar with several cross members, the top is covered with 1/4" hardware cloth (metal screening) to keep out the critters.  In the winter the cover is wrapped with 4 mil plasti , the plastic sheeting is wrapped around both sides of the top to make a 1 1/2 inch thermal barrier and the void is filled with the large size bubble wrap.  The top is typically propped open but on the coldest days the top is left closed- not air tight.  The bottom is excavated about inches below grade, the botom has a geotextile liner to reduce the amount of tree rots and filled with about 2-6 inches of builders sand.

This frame holds Scilla from North Africa, hyacinthella, hyacinthoides, crocus, polyxena, miniature narcissus, and the smaller onco iris.  The plants are both in plastic and clay pots  and the iris are planted directly in the sand.  The pots are typically plunged in the sand with sand on all sides. These plants bloom in season all winter long while the outside condition could be 1-2 feet of snow cover or the more typical black frost- very very cold (-20 to -35 C) with no snow cover.  The frame is not level much to the dismay of local rock gardeners but i like this design as the upper level gets more sun and is dryer for the onco irises the lower end is damper for the rarer scilla and hyacinthoides.

The deeper frame is adjacent to the house foundation and extends about 2-3 feet below grade and is used to store non-hardy or early emerging hardy plants that cannot be planted outside or are better grown in pots. the top design uses typical polycarbonate cell covers that are removed in summer to reveal the top screens.

These photos are from last fall and winter 2012-13

[annew]

They look the business, Rimmer. Interesting hinged stays too.

[Rimmer de Vries]

The stays or props are not my design, but it is just a thin piece of lumber with one dry wall screw fastened near the front of the lid.  The prop swings forward to hold the top open when you lift the lid - good when you approach with full hands.  But to close you need two hands, one to push back the prop to close. 

[pehe]

Hi Rimmer,

I have several smaller home made frames.


The seed frames are simple wooden boxes. They are normally open, but can be covered with a 1mm thin polycarbonate sheet, which are bent and pushed down between the pots and the wooden sides. It forms a small tunnel with open ends.
The frame dimension is 45 X 45 X 150 cm and they are filled with sand. The pots are placed on top of the sand.

Another frame is used for growing bulbs which need cool and humid conditions: Crocus banaticus, C. scharojanii, C. pelistericus, C. autranii etc. The problem with them is to keep them cool but at the same time give them a lot of light.
I have solved that by making the frame of 5 mm polycarbonate sheets screwed together. The backside wall is white to avoid too much heating from the sun and at the same time reflect as much light as possible to the plants. The pots are plunged in sand again to keep them cool. The sand are always moist.
In the summer the frame are open, but covered with netting to keep out snails, mice etc. (and my cat!). If it is very hot the frame is shaded. In the winter it is glass covered.

Poul

[johnralphcarpenter]

That's real craftsmanship!

[Rimmer de Vries]

That's real craftsmanship!

I second that! wonderful design.

Poul, how cold does it get in your area?

[pehe]

Thank you Ralph and Rimmer!

The lowest winter temperature I have recorded is -23 ^oC. (The record is -31) In a 'normal' winter the lowest temps are -15^oC in some nights and periods with day temperatures around -5 often followed by days with rain and +5^oC. Here the winter wetness is the worst bulb killer.

Poul

[annew]

Poul, your frames are very smart. How did you bend the plastic sheeting at the corners?

[johnw]

That's real craftsmanship!

John -  Remember he's a Dane, nothing in half measures you know.

johnw

[pehe]

Poul, your frames are very smart. How did you bend the plastic sheeting at the corners?

Thank you! Wish I could grow Narcissus as you!

I am lucky to have access to a mechanic workshop with many machines among them a manual bending machine where the polycarbonate can be bent quite easily. Polycarbonate is very tough, it will not crack or splinter and can be bent at ambient temperature.

At first this frame was made with wooden sides, but as it is quite narrow, the flower stems and the leaves grew long and floppy reaching for the light. It is much better now.

Poul

[brianw]

I have to ask a basic question. What is the difference between a cold frame and a bulb frame? Is the latter the former with bulbs in, or something more?
I think of a bulb frame as a glazed all round top on a sand filled plunge frame, often well above ground, in the UK climate at least. Open at the sides in summer maybe. A cold frame a largely shady box with "glass/plastic" just over the top. If you put shade loving bulbs in the latter does it make it a bulb frame 
Many of them above seem to be what I call a cold frame.

[Rimmer de Vries]

Hi Brain that is part of the purpose for this thread to see what people call a bulb frame.  please can you show your bulb frame.

I call my frame a  bulb frame as it contains bulbs. but it cold be called a cold frame except in the summer when rain is expected I cover with plate glass sheets.

Rimmer

[brianw]

Hi Rimmer
I have never had a "bulb frame" as such. My bulbs survive either in the alpine house mixed in with other alpines, or in temporary cold frames built as necessary, in semi shade on the north side of the greenhouse, or against the south wall of our house in winter for the larger tender plants in general. I have a small frost free greenhouse for other plants.
I am now starting a new garden but don't plan any bulb frames as such, just cold and frost free greenhouses and some cold frames on the north side of the greenhouses. The plants I currently store in the winter south frame may end up in a garage in future, if the frost free is full, so light may be a problem.