Gardening Tips for July 2025

Have you ever thought about mulching? A daft word used for a few hundred years and of undefined origin meaning a covering to keep the surface underneath moist. So why bother to do that, how to do it and to do it with what?  This is your mulching guide and could be just what you are looking for to ease the graft of gardening.

Mulching is an attractive vocation to the gardener because it can reduce the amount of work needed and depending on where it’s put, can increase the yield of the garden. There is no real point in mulching if the process doesn’t bring any benefits, so successful mulching is the order of the day.

Mulching is the time-honoured practice of covering the ground with unrotted (usually) organic material such as bark chippings, lawn clippings or straw (I wonder what strawberries would have been called had they been mulched with cow m***/manure?) that is spread onto the ground and simply leaving it there.  The soil underneath can then benefit from protection from erosion, nutrient input from the breakdown of the mulch, protection from temperature fluctuation, provides a barrier for edible crops, looks neat and tidy and best of all, weed suppression.

There are basically two groups of mulches, those that rot down into the soil and those that don’t. The ‘don’t’ group tend to be used for decoration such as a layer of gravel on a planted pot or sheets of landscape fabric (see later).  Whatever is used, a mulch should be permeable to allow water to penetrate the ground below.

Organic, biodegradable mulches to just leave on your garden to rot down into the soil, include:

• Wood bark and wood chippings (eventually become part of the soil)

• Leaf mould (fallen leaves collected in autumn and left in a heap or bags to decompose)

• Garden compost or well-rotted mature

• Straw for strawberries

• Spent hops from the brewery (beware, poisonous to dogs - not sure about cats and children)

• And best of all, a product called Strulch (other commercial products are available) which is made from straw with a few active organic ingredients to nourish plants and deter pests.  It lasts for two to three years, is easily incorporated into the soil, smells and looks great and comes from Yorkshire, what’s not to like!

Inorganic, non-biodegradable mulches can be incorporated into the soil depending on type and size of the aggregate; they are used mostly for decoration and are probably best laid over a sheet of landscape fabric to stop them being lost in the soil.  They don’t do anything to improve the fertility or structure of the soil (although fine grit can improve drainage in clay soil but that required digging in which isn’t the point if using as a mulch), however they do suppress weeds, conserve moisture and, one hopes, look decorative.  Examples of these mulches include:

• Slate

• Shingle

• Pebbles

• Gravel

• Stone chippings. 

Dark coloured material will warm the soil in the sun whereas light coloured mulch will reflect sunlight and keep roots cooler in strong sunlight.

Sheet mulches or woven landscape fabric (plastic free only) can be used for new beds or borders. After laying, slits can be made in the fabric, allowing planting through it. The downside is these mulches do not look very attractive, but they can be covered (mulching your mulch) with additional mulch of your choosing.

So, I’ve decided to mulch, but when is the best time to do it and how?

A good rule of thumb is mid to late spring, autumn or anytime when planting something new.  Simply spread out on your chosen spot to about 50 mm depth, stand back and admire.

Keep gardening.                                                                                        

Richard Haigh