the essentials in brief
- Ripe compost and fine-grain quartz sand (€ 14.90 at Amazon *) are tried and tested means of improving compacted, wet clay soil.
- Permanent protection against waterlogging is guaranteed by drainage in the clay garden soil with a drainage trough.
- Roses, hydrangeas, apple trees and many other plants like clay soil when rainwater infiltration works.
Improve clay soil - this is how it works
Loam soil has a very fine-grained structure that tends to become heavily compacted. A high proportion of sound exacerbates the problem. The earth becomes so firm and sticky that plant roots are slowed down in growth. Rainwater cannot or only very slowly drain off. The fatal consequence is waterlogging in the upper soil layers, recognizable by puddles in the lawn and bed. As a result of the water saturation, valuable lime is washed out, whereupon the pH value drops and the garden soil acidifies. It doesn't have to come to that if you loosen up clay soil and make it more permeable. How to improve clay soil with horticultural expertise:
- Dig up the earth as deep as a spade, rake vigorously, remove weeds, stones and dirt
- Work ripe compost soil into the clay soil (3-5 l / m² at least)
- Smooth the improved clay soil with the rake
- Spread the sand in a layer height of 2-5 cm and rake in
- Measure the pH value with a test set from the hardware store
- Liming the garden soil with a result below a pH value of 5.5
also read
- Planting flower boxes for the balcony correctly - this is how it works
- Plant on clay soil
- Perfect ground preparation for turf - this is how it works
From now on you dig the clay soil one or two spades deep every year before the first frost. Temperatures below freezing point freeze the water in the ground. Small ice crystals form, which burst the compacted earth and thus loosen it up. In addition to the frost bake to loosen the soil, sow green manure in spring with deep-rooted plants such as lupins (Lupinus), red clover (Trifolium) or marigolds (Calendula).
Special case of clay soil under lawn
Compacted clay soil makes life difficult for the noble grasses in the lawn. The tender roots can hardly penetrate a compact crumb and drown in waterlogging after every downpour. To avoid having to clear the lawn to improve the clay soil, rent or buy a manual or motorized lawn fan, also known as an aerator or aerator. How to proceed correctly step by step:
- Mow, scarify and sweep the lawn
- Aerate the surface with 200 holes per square meter
- Sand and irrigate aerated lawn
- Repeat the measure every year in March / April and September / October
The above procedures are helpful when there is no drainage in clay soil. At least for some time you can use this method to drain waterlogged garden soil. Are you interested in permanent rainwater infiltration? Then the effort and expense of a pipe system with a drainage pit is worthwhile. Tips for uncomplicated DIY drainage in the garden clay soil can be found in the next section.
Creating drainage in the garden clay soil - tips
Lawn will not grow on clay soil if the rainwater stops. Annual scarifying and aerating only solves the problem temporarily. If flowers, shrubs and vegetables stand with wet feet after every heavy downpour, growth depression and bad harvests are inevitable. Affected gardeners tackle the problem at the root with permanently improved rainwater infiltration. The following tips outline a simple variant of how you can use drainage to make clay soil with waterlogging more permeable over the long term:
Preparatory work
Measure the course of the pipe system for the drainage to the infiltration system exactly. Then you create a detailed plan sketch so that you can precisely determine the material requirements. On the shopping list, make a note of slotted drainage pipes that are coated with coconut fiber. The special drainage pipes lead into a collecting line that lets the water flow into a drainage basin. In addition, you need sand, gravel, grit, (€ 12.80 at Amazon *) seepage fleece, wooden slats as formwork, spade, shovel, ideally a mini excavator or strong helpers for the sweaty excavation work.
Lay the drainage pipes and collecting line
A slight gradient of 2 to 3 percent is of decisive importance for the functioning of a drainage in the garden clay soil. Regular checks with the spirit level guarantee that this important premise is adhered to when excavating the clay soil and then filling the ducts. In addition, the following guidelines are relevant so that rainwater infiltration in the garden becomes a successful project:
- Dig channels for the drainage pipes (15-30 cm under lawn / turf, 80-150 cm under vegetable patch and orchard)
- Use wooden boards as formwork in the pits
- Line pipe ducts with seepage fleece
- Fill in a layer of sand as protection for the fleece and the gravel packing over it
- Lay the drainage pipes and collecting line
It is important to note that there is sufficient distance between the drainage pipes and the basement of your house so that you do not have to struggle with wet basement walls. It must be ensured that rainwater from the drainage line does not get into the house's drainage shaft and flow into the sewer. Under these circumstances, trouble with the authorities is inevitable and sewage charges skyrocket.
Drainage basin
A drainage basin solves two problems in one operation. If the size of the garden area allows it, the hollow functions as a collecting basin for the collecting line of the drainage pipes and blends harmoniously into the creative garden design as a natural wet biotope. The following overview summarizes the key points:
- Dig out the drainage basin below the collecting line of the drainage pipes
- ideally dig into a permeable soil layer at the site (no gravel packing or filter fleece necessary)
- Alternatively, line a dense clay soil as the bottom sole with fleece and fill it with sand and seepage gravel
In contrast to the drainage shaft on the house, a simple drainage in the clay garden soil does not require a building permit. This requirement applies as long as the construction is limited to optimizing the natural rainwater infiltration in the lawn or garden soil. Any additional measures for the drainage of clay soil are subject to legal regulations such as the Water Management Act or the building regulations. In many municipalities, it is also prohibited to drain rainwater into the public sewer system using a garden drainage system. Therefore, please contact the responsible authority if your plans go beyond the simple drainage variant explained here.
Tips
The visible part of a garden drainage system is the drainage basin as a wet biotope. The pipes resting in the ground were quickly forgotten. Photograph the course of the pipe system and keep the photos together with the plan sketch so that there are no nasty surprises later when working on the ground in the bed.
Ideal Plants for Clay Soil - Premium Selection
Which plants actually like clay soil? Which trees grow on clay soil? To save you a long headache, we have put together the following table. These plants prefer to grow their roots in nutritious, heavy loam soil:
| Perennials / vegetables / herbs | botanical name | Shrubs / ground cover | botanical name | Trees / fruit trees | botanical name |
|---|---|---|---|---|---|
| Aster, rough-leaf aster | Aster novae angliae | Roses | pink | Sweetgum tree | Liquidambar styraciflua |
| Flame flower | Phlox paniculata | Hydrangeas | Hydrangea | Trumpet Tree | Catalpa bignonioides |
| Sun bride | Helenium | Black currants | Ribes nigrum | Redwoodtree | Metasequoia glyptostroboides |
| Bergenia | Bergenia | White willow | Salix alba | Sycamore maple | Acer pseudoplatanus |
| Splendid spar | Astilbe | White dogwood | Cornus alba | Spruce | Picea |
| Peony | Paeonia officinalis | Purple willow | Salix purpurea | cedar | Cedrus |
| tomatoes | Solanum lycopersicum | Shade green | Pachysandra terminalis | Apple tree | Malus domestica |
| Potatoes | Solanum tuberosum | Loquat | Cotoneaster procumbens | Plum tree | Prunus domestica |
| Onions | Allium cepa | Button bush | Cephalanthus occidentalis | Cornelian cherry | Cornus mas |
| Carrots, carrots | Daucus carota subsp. sativus | Red winter berry | Ilex verticillata | quince | Cydonia |
| Cabbage of all kinds | Brassica | Hornbeam | Carpinus betulus | Sloe (large shrub) | Prunus spinosa |
| chives | Allium schoenoprasum | Clematis | Clematis | Black elder (large shrub) | Sambucus nigra |
| peppermint | Mentha piperita | yew | Taxus baccata | ||
| thyme | Thymus vulgaris | Tree of life | Thuja |
The best lawn seeds for clay soil should primarily consist of deep-rooted grasses, such as the Lägerrispe (Pos supina). When selecting the type of lawn, a distinction must also be made as to whether it is a location under sun or shade. A look at the back of the packaging provides more information.
Digression
Buy clay soil
Building on clay soil leaves a massively compacted soil crumb. Instead of devoting yourself to extensive soil improvement and drainage measures, you can remove the dense, waterlogged soil layer and buy fresh clay soil of the best quality. Sources of purchase for clay in top form are local building material suppliers, container services and composting sites. Civil engineering companies and horticultural companies have high-quality loam soil on offer at low prices as topsoil.Dispose of clay soil properly
If you no longer have any use for clay soil after it has been stripped, you have various options. How to dispose of clay soil in an exemplary manner:
- Sieve clay soil, transport it with a trailer and hand it in to the horticultural company or the municipality free of charge
- Rent a truck and driver, shovel clay on the loading area and let it drive off
- Publish sifted clay soil (without rubble) in soil exchange for self-collectors
- Assign disposal to a specialist container company
It is important to note that, despite all the complaints, the loam soil that has been removed is still a living natural asset that must not be carelessly destroyed.
frequently asked Questions
How to prepare clay soil for lawn
Lawn grasses want their subsoil to have a loose, permeable consistency. So that compacted, waterlogged loam soil enjoys the benevolence of the noble grasses, create a coarse subgrade and a fine subgrade in two steps. In the first phase, you dig up the clay soil, removing roots, weeds and stones. Then work in lawn sand at 4 kg / m² and let the rough level rest for two weeks. For the fine subgrade, rake, weed and rake the improved loam soil until a fine crumbly consistency is obtained.
Which sand is best for clay soil improvement?
Fine-grain quartz sand is a good choice for allowing rainwater to seep away faster in the dense clay soil. However, the first choice is comparatively high with an average price of 0.24 euros / kg. Soil improvement is cheaper with fine-grain, washed construction sand, which costs 0.12 euros / kg.
In our garden, sandy loam soil allows rainwater to seep away far too quickly. What to do?
Ripe compost and bark humus improve the water storage capacity in sandy loam. The higher the proportion of sand, the more organic soil additives you should incorporate. Green manure every spring is beneficial for the soil quality. Plants such as lupins, bee friends, marigolds or red clover enrich sandy loam soil with green and root matter so that soil water does not seep away so quickly.
Tips
If clay soil had a say in the garden, lava granules would be at the top of the wish list for soil improvement. Cooled lava with a grain size of 4-16 mm or 16-32 mm effectively prevents unfavorable compression and the resulting waterlogging. Because lava granulate (€ 10.95 at Amazon *) does not rot, loamy garden soil benefits from reliable rainwater infiltration for many years.
