A whole range of GARDENA Newsletter readers have sent us their questions about lawns in recent weeks. Thank you! However, in the Newsletter itself we can only ever answer three or four questions. For this reason, we have grouped the lawn questions together and answer them here in this Lawn Special. And because not everybody is interested in everything, we have organised the information alphabetically using keywords. Simply scroll through the good two dozen keywords to find the advice of your GARDENA garden expert - and enjoy a fantastic lawn season!
Today, your GARDENA Newsletter has answers to questions from A for aerification to M for moss in lawns. In Part 2, you will find information on lawn types, turf, removing weeds, and scarifying. So here is Part 1 of the Lawn Special!
Yes, this term really does exist and we are happy to explain it to you! It concerns the ventilation of grass roots. Lawns are often on soils that are not sufficiently sandy, so too little air reaches the roots - which need to breathe. As a result, the soil is too cohesive and lawn growth is stunted. Aerification - the addition of air - can help. Special gardening and landscaping devices are used to stamp holes into the lawn. These holes are then filled with coarse sand so they do not become muddy. Surface water now flows away better and the grass roots get more air - to ensure better lawn growth. On small lawns at home or in problematic areas (e.g. where the soil is particularly clayey and/or has standing water), you can aerify the grass with a digging fork.
We understand that you find them annoying! At home, they are mainly found near path slabs or stepping stones on lawns - they are less prevalent in the middle of lawns. They tend to produce sand piles rather than actually damaging the lawn itself. Ants can be combatted with ant-killer or - in smaller areas - baking powder spread in dry weather. Please note that large wood ants cannot be killed as they are a protected species. They can be found in areas which are close to woods.
If you are about to plant a lawn, do not use just any seed. There are now labour-saving seed mixes which grow flatter and around a third more slowly. This means less mowing for you and fewer trimmings to remove.
Well, these are a matter for debate. Personally, I don't like planting trees in lawns because fallen blossoms and leaves annoy me and lawns need to be cleared more quickly than beds to prevent damage to the grass. And I don't like mowing round them either. Why create even more lawn edges to care for? But if there are already trees in your grass, you really should create a separate tree pit so that the tree's roots get enough air. Especially on loamy soils, the roots tend to come to the surface. This means that in the case of older trees the roots are constantly hit by the lawnmower. And the bark can just as easily be bumped and damaged if the grass goes right up to the trunk. So the tree pit has two functions: It provides distance from the mowers and cutters and protects roots. However, this does not work if you pack in the mulch so tightly that the roots below it cannot breathe anyway! It is better to keep it loose and hoe it every now and again.
Some lawn areas, which are woven through and through with for example speedwell, white clover and daisies, involuntarily or passively become flowery meadows. If you do decide to sow a meadow in your lawn, it should be clear that it will severely limit the use of the area. The flower meadow is not built for regular, frequent use. You can use standard commercially available seed mixtures for the purpose. They contain a variety of different grasses and herbs, of which short-lived ones such as cornflowers and poppies will not live long, and of which those varieties will remain in the area long-term which can cope well with the location. You are correct in your assumption that you will then have to mow your lawn less. Twice per year is then perfectly sufficient (once in June, and then again in October). However, you will then have to cope with larger quantities of mown grass, and require a scythe, motor-drive scythe or a cutter bar rather than a “normal” small garden lawnmower. Some flowering lawn owners only mow once, in September. They wait for the seeds of most of the flower varieties to ripen, which has not usually comprehensively taken place in June.
People often forget to add lime to their lawns. But the growth of lawn grasses is often restricted if the soil is too acidic, as is the case for fescue grass. The ideal pH for lawns is slightly acidic - between 5.5 and 6.5. Around 50 to 60 grammes of agricultural lime per square metre per year is enough to maintain lime levels. Sandy soils usually need more lime more frequently than clay soils which bind lime better. If you are able to determine the pH value of your lawn yourself with a soil probe, add 60 grammes of lime per square metre to raise the pH value by 0.5. Example: You measure a pH of 4 and want to increase it to 6; you need 4 x 60 grammes of lime per square metre - around 240 grammes. A 25 kg sack is therefore enough for a good 100 square metres of lawn.
When you dispose of cut plants on a compost heap it frequently starts to smell. This happens if you place the cut plants in thick individual layers on the compost. To prevent a stink, use thin layers of grass trimmings which are no more than around 10 cm thick. Then alternate with layers of very dry composting plants (e.g. dry stems chopped in autumn or thin branches cut from trees). This mixes dry, carbon-rich composting plants with damp, nitrogen-rich ones - for the best possible rotting conditions. This is especially true if the composting materials - as shown here - are well ventilated in layers. Anaerobic conditions are not present - meaning no foul gases and no stink.
Yes, they make mowing lawns easy, because ideally they cut up the trimmings so small that they can fall onto the ground between the stalks and decay there, thus providing nutrients for the grass. But you have to be aware that this really requires a good lawn base and healthy, well-fed grass. It does not work so well on problematic soils (too compacted or too wet). In such cases, the trimmings remain between the stalks for too long in the form of a layer which prevents the flow of fertiliser, hides the stalks from the light, and encourages the growth of moss. So: Use your mulch mower but use a scarifier at least once - and more often if necessary.
Delay sowing new seeds until the soil temperature has reached around 14 degrees. The seeds will then germinate more quickly and the young plants will grow faster. Depending on the seeds used, around 30 to 40 grammes per square metre is sufficient. If you are less experienced at spreading fertiliser and cannot rely on intuition to get an even spread, use a fertiliser spreader which also has a setting option to ensure even seeding. Don't forget to roll the seeds in afterwards! If you want or need to water the seeds in the fourteen days or so before they germinate due to really dry weather, do so very carefully so you do not flush them off the surface - this requires a delicate touch, especially on slopes. People often ask when it is best to mow for the first time: Wait for three or four weeks and then only mow if the lawn is starting to green over, when the stalks are around eight centimetres long. Cut it to around five centimetres now; when the grass is mown for the third or fourth time and is thicker, it can be gradually cut to three centimetres.