If you have made a rock garden or raised bed by following the basic rules, then routine maintenance should be a straight forward task. It will not call for skill as required in the pruning of fruit trees nor the heavy work demanded in the vegetable plot. You should not be troubled by weeds for some time and the plants will flourish in the well drained, gritty conditions you have provided for them. But regular maintenance is not something you can ignore. Leave a shrub border untended for a season and no great harm may result, but leave a rock garden for a year and it may well be ruined.
Treat rock garden care as a routine once-a-week job during the growing season, in the same way as you may treat house plant and lawn maintenance. Weed control will be the major task. Keep the area free from dead plants and debris, and water only when necessary. Dead-head spent flowers where practical, especially if the variety can become a nuisance by self seeding. Label plants which die down for part of the year.
Autumn is the major overhaul time of the year. All fallen leaves must be removed and the stems of rampant plants must be cut back. Do not leave this job for the spring. Cover winter sensitive plants. In spring renew the grit mulch, feed, remove winter protection, firm plants which have been lifted by frost and look for slug damage.
All this advise may have come too late – the rockery may already be over-run by weeds and it is covered with straggly rampant alpines due to past neglect. There is no easy answer. You will have to start again. Remove the soil from affected area, replace it with new planting mixture and then replant.
Weeding Your Garden:
Weeding your garden is one of the most tedious of all maintenance jobs, and prevention is so much easier than cure. Begin at construction time, make sure that the planting site is free from all perennial weeds and that weed roots are absent from the topsoil used for making the planting mixture. As described below, a mulch of grit on rockery and raised bed gardens or bark on peat gardens will help to prevent weeds.
It is unfortunate that however careful you are at the construction stage, weeds will still appear and they must be tackled promptly as dwarf plants such as alpines can easily be swamped by them. There are a number of sources of these weeds, and you can cut down the work of weeding if you take preventive measures. Firstly, weeds are often brought in with the plants, always check carefully and pull out stems and roots of any weeds which are growing on the soil surface of the pot.
Next, perennials can creep n from surrounding land so try to create some form of weed-proof barrier if this is likely. Finally, weed seeds are blown on to the site – remember that this includes the seed from nearby rock garden plants which readily produce self-sown seedlings. Dead-heading and weed control in surrounding land will reduce this problem.
Hoeing is not practical where a grit mulch is used. Pulling out weeds by hand is the usual way to tackle the problem, you may need to trowel if the roots are firmly anchored. Of course not all self-sewn alpines are weeds, you will only need to pull out seedlings which are growing where they are not wanted. Perennial weeds are a difficult problem when the roots are too deep and widespread to be removed. The answer here is to paint the leaves very carefully with glyphsate – never spray weed killers ans never use lawn-type ones.