A great British summer of colour

Monday, 19 August 2019 | Gardener Expert
Posted in Garden Trader Blog, Gardening Advice

A great British summer of colour

What can we say about this year’s weather?  A great spring and fantastic summer to date, which has helped gardeners get the best out of their gardens, in terms of a splendid splash of colour and some decent grass growth.  A recent trip to a garden centre whilst on holiday in Pembrokeshire, Wales, enabled me to see an array of plant material that has become popular in gardens in recent years.

We now have a wider choice of plant material than perhaps our parents and grandparents had, with many nurseries offering a wide selection of hardy, half hardy and annual plants for sale.

This is coupled with the fact we now have a fine selection of tools and aides to help make the task of gardening much easier.

I particularly like the Alliums that are available in shades of blue, purple, mauve and white and with a range of flower head sizes from just a few centimetres to 18-20cm (7-8in) in diameter.

As for height they can be majestic, some reaching over three feet, and you can plant them in the middle of a border where they can stand above shorter, neighbourly plants.

Other plants that have done well this year and provided a cascade of colour are our roses that have flowered continuously from May through to September.

As for herbaceous plants, we are spoilt for choice, with many now showing at their best. I particularly like the Kniphofias (red hot pokers) that provide a splash of colour and form in shades of red, yellow and orange.

However, for me a garden would not look at its best without a manicured well-maintained lawn.

A well-maintained lawn requires, after a long period of growth, a complete autumn renovation to clean out any dead and unwanted lateral side growth, aerating and re-populating with some new seed.  Commonly known as an autumn renovation.

This work should generally be carried out in September before soil and air temperatures drop into single figures.


The benefits of an autumn lawn renovation are numerous giving you the opportunity to:

  • · Clean out surface moss and fibre
  • · Aerate/de-compact the soil
  • · Topdress with a sand/soil dressing to maintain surface levels
  • · Overseed with some new grass seed to repopulate the lawn, sowing at a rate of 35-50 grams M2
  • · Apply an autumn NPK base fertiliser

The first job is to clean off as much vegetation as possible and remove any unwanted organic matter / thatch by the process of mowing, scratching, scarifying and sweeping the surface prior to topdressing.

You really need to remove as much dead matter and thatch out of your lawn as possible, scarifying in 3-4 directions to remove all the dead fibre / thatch.

Then re-instate dips and hollow and restore levels with appropriate amounts of compatible root zone dressing 70/30 ratio of sand and soil material and then overseed with a desirable quality amenity grass seed mixture.

Thatch is a tightly intermingled layer of living and dead stems, leaves and roots which accumulates between the layer of actively growing grass and the soil underneath. Thatch accumulates when the production of dead organic matter exceeds the rate at which it decomposes.

The first task is to mow the lawn as low has you can get with your mower, then use a combi rake to scratch up any remaining prone grass growth and then re-mow the square or use a brush / vac to clean up the surface.

The next task is to scarify the lawn. Scarifying is a process perhaps best described as a mechanical raking. A scarifier uses a series of sharp blades that rotate at high speed and cut into the turf in a vertical manner. Always scarify to a depth suitable for your lawn, i.e. to below the depth of thatch.

Scarification is important to remove unwanted vegetation, but also to produce a key for the rootzone topdressing and seed to sit in. The level of scarification required will be dependent on how much of a thatch layer you have generated throughout the season. Scarifying in at least three directions, never scarify at right angles to the last pass as this can pull blocks up and severely disrupt the surface.

Where necessary, clean off all the thatch debris after each pass. The square can then be oversown using a suitable grass seed mixture; do not be frightened to try out new cultivars. Sowing rates now range between 35-50 grammes per square metre. In essence, you are aiming to establish new grasses into your square.

Your topdressing materials can be applied in various ways, by hand or using a drop / cyclone type of spreader. If this is being done purely to smooth the lawn then you can apply at 3 to 4 kilos per square metre which will give about ¼” or just over half a centimetre in depth. Obviously, the dips will get more but you must not smother the grass. The rule is 75% of the leaf must be exposed.  

Ensure a good seed pattern during renovations. The best method is to use a dimple seeder and make many passes but, if this is not possible, use scarifier grooves, even applying seed in between scarifier passes whilst the slits are open, since only a small proportion of the seed will be picked up in subsequent passes. The seed must be in good contact with the soil or it will not grow.

Aim to complete all renovations by the end of October at the absolute latest, and preferably sooner, ryegrass needs a soil temperature of above 5.5 °C in order to germinate. With favourable temperatures, the seed should germinate between 7 and 14 days. Water the seed if necessary and keep moist until the grass plants have established.  

A pre-seeding fertiliser can be used to help promote some growth, something like an 8:12:8  NPK or even a 7:7:7 NPK at 35g/m2 will be ideal, though you should be careful not to use anything with iron in at this stage as it can acidify the surface and damage the new grassplants.  It will then be a case of allowing it to grow to a height of around 40mm before giving its first cut using a rotary mower.  

Regular mowing when the grass is growing will maintain the sward health. Certainly, do not allow the sward to grow above 25mm when established or else there will be a loss in density.

Feed through the winter months too! Grass needs much less nitrogen through the winter months, but that does not mean that it needs none. Applying a low nitrogen feed, which is high in potassium, will help the grass plant recover from damage and stress and keep red thread at bay.

The benefits of all this work will be seen next year.