Construction of pits and installation of the frame for classic Russian hotbeds

Preparing the pit for a classic Russian hotbed directly influences the temperature regime and the ease of plant maintenance. The depth and shape of the trench are chosen based on the purpose of the hotbed and the soil texture. The walls of the pit are made vertical, forming slopes only in light soils prone to caving.

During excavation, it is important to consider the height of the future paths. The pit is dug slightly shallower than the design depth, as the excavated soil is piled onto the paths between the hotbeds, artificially increasing the height of the walls. The final depth is measured strictly from the bottom to the top edge of the southern longitudinal log (frame base).

• Depth for early vegetables in the first rotation — 75 cm
• Depth for growing transplants — 50–60 cm
• Width of the pit at the top — 145 cm
• Width at the bottom in light soils — 110–120 cm
• Width at the bottom in dense soils — 125–180 cm

In areas with a high water table, additional protective measures are required. Excess soil moisture interferes with proper soil warming and can cause root rot. In such conditions, drainage must be installed at the bottom of the pit.

1. Dig a drainage ditch 15 cm deep and 20–25 cm wide along the bottom of the pit.
2. Extend the ditch outside the hotbed into a specially dug deep hole.
3. Fill the ditch tightly with brushwood to prevent silting.
4. Establish a general drainage network throughout the hotbed area.

Frame Assembly and Selection of Materials

The standard wooden frame (rim) is assembled from round logs 12–14 cm thick. To ensure maximum sunlight access for plants, the longitudinal logs on the south side are laid directly on the soil, while those on the north side are raised by 20–22 cm. If the site has a natural slope to the south, the raising height of the north side is reduced accordingly.

For a standard 20-frame hotbed, longitudinal logs 4.27 m long are used, with the four end logs being longer — 4.5 m. The length of the transverse crossbars (struts) is 1.94 m. On light sandy soils, 1–3 log rims are laid on the south side and 1–2 rims on the north, adjusting the wall stability and the angle of the frames.

In case of a shortage of logs, the frame is assembled from coniferous boards or slabs. The connection of longitudinal and end boards is performed rigidly — using "butt-to-post" or "interlocking" methods to avoid deformation and settling of the walls. To maintain the shape of the box, transverse braces are placed between the frame bases, positioning them at the joints of the boards and in the middle part of the walls every 2–4 frames. The braces must be at least 8 cm above the level of the hotbed soil.