How to grow roses: Soil Preparation
Best conditions for root development is in deeply aerated soil. With complimentary additives virtually any soil can be improved. Planting roses in individual holes restricts root development; comparable to growing in pots. Only for roses to be grown as specimen bushes, shrubs or climbers are individual holes (1m wide x 60cm deep)to be dug. For rose beds the whole area should be prepared and for rows of roses trenches need to be dug.
How to prepare your soil
- Demarcate the border of the bed or trench.
- Dig up and shovel the top 40cm to the sides of the bed.
- Loosen the now bared subsoil by another 20 to 30cm depth. Stones to about fist size with surrounding soil assure permanent aeration.
- Water-holding subsoil is unsuitable for rose growing UNLESS a drain pipe can be installed on sloping ground or create a raised bed about 50cm higher than the surrounding lawn or pathway.
- For sticky clay or turf add gravel, coarse sand, clinker ash, peach pips, nut shells, perlite or crushed styrofoam as well as liberal quantities of organic material such as coarse compost, pine bark mulch or chips. coir (coconut fibre) and best of all peanut shells. Mix well.
- For very sandy soil liberal water retaining organic material such as peat moss, coir (coconut) fibre, peanut shells or compost is dug in. A mat of rock-wool or other heat insulation material i.e. “think pink”, thick news papers may be spread out over the loosened sandy subsoil in order to trap and retain drain water.
- A similar decision is made to create a relative permanent good aeration of the soil that was shovelled to the side and needs to be filled back into the bed enriched with nutritious material. Any of the above maybe used as well as compost and matured manure. For accuracy it is best to shovel about half of the excavated top soil back and spread out evenly over the prepared subsoil. Add a 5 to 10 cm layer of the available or decided on additives, sprinkle a handful of superphosphate or two hands full of bone meal per square metre and proceed to dig it over and get it mixed. Proceed by spreading the balance of the top soil over the prepared soil, again adding 5 to 10cm additives and superphosphate / bone meal and dig over. By now the surface of the prepared bed should be about 30 cm higher than the surrounding level. A spongy effect should be evident when stepping on it.
- In many gardens one encounters only about 0.30 m good sandy soil with a meter thick layer of dense clay or turf. It makes no sense in digging and excavating deep into it, creating a mini swimming pool in the process. Rather enrich to upper good 0.30 cm with additives as explained and then bring in more top soil and additives, raising the level to about 0.50 m above the level of lawn or paving. To prevent the edges from being washed out a wall can be built with stones, bricks, wooden planks or poles or planted up with ground hagging low growing plants such as the Australian violet, wild or edible strawberries, Periwinkle – the list is long.
Compacted soil locks up many important nutrients and it requires humus (described as “organic constituent of the soil formed by the decomposition of plant material) to “unlock” such nutrients.
The raised level of the soil of the rose bed or individual hole is most important. It allows superb aeration and prevents standing water in the level where the roots are most active. In time with the decomposition of the large quantities of plant material (compost) the level will drop, but not to an detrimental sunken bed.
When it is found that the soil is too sandy, as is often then the case near the sea, and without large quantities of water holding material being available it is best to sink large plastic pots, even half 100 or 200 litre plastic drums with holes cut into the bottom into the sand and to plant the rose bush with potting soil into the pots. The same applies to positions when encountering dense roots from nearby trees or climbers when digging holes or beds. Such tree roots would quickly throw an even denser root net above the roots of the newly planted roses not giving them a chance to develop. Again, planting the roses in big pots sunk into the soil with just the rim sticking out will solve this problem.