WHAT IS MULCH?
A definition of mulch is that it is a protective material, of various sorts, both organic and inorganic, that has several important tasks to perform in any type of garden. It is put onto the surface of the soil immediately surrounding your plants thus creating a protective kind of ground cover and when you think of it, nearly anything can be used for mulch, even torn up newspaper (only use the black and white pages though, no coloured ink ones).
It has several well established uses for the container gardener. ORGANIC mulch includes wood chips and bark, grass cuttings, straw, ‘healthy’ fall and pruned leaves (i.e. not diseased), pine needles, compost, and in some cases fibre from juiced fruits and vegetables. Perhaps you can think of others? I also use under planting of ground covers and certain hardy plants as a living mulch with much success.
For instance, under a rose box that we have in the front entrance to our building we grow spider plants and miniature ivy. This offsets the multicoloured rose bed so nicely. It would be fair to say that organic mulching is more popular for gardening purposes while inorganic mulch is probably more widely used for aesthetic and design affects. INORGANIC mulch includes rocks and pebbles, stone chips and even rough sand; plastic, bone, shredded rubber, plastic and glass. Of course mix and match also does well. In the right situation, an inner ring of bark chips can look very striking with a surround of pebbles. Do you live by the sea? Seaweed mulch is really good, and if you know a friendly farmer then ground mielie/sweetcorn cobs and wheat chaff are good too.
WHERE TO MULCH?
By definition, mulch goes on the top most layer of your pots. And then as it works its way down, it breaks down or is dug in by you, and will be replaced with a similar and new layer. By the by, I have a friend with an all rose container patio who had used smooth flat palm-sized brown pebbles to outline one of the corners of her potted deck. The effect is quite impactful and while it is not mulching in the strict sense of it all, it really does enhance that corner and connects her containers with flair. It looks as if she has outlined a garden pathway of sorts.
WHEN TO MULCH?
...all the time especially in sunny hot climates and on hot sunny days. But there are so many reasons to mulch that you should just mulch – a reason to suit will find a home wherever your containers are placed and no matter what you are growing. The only time you would not mulch is a traditional sense is with a container fully planted with a border style planting or meadow mix. But then here, compost on the surface could work as a nutrient giving mulch anyway.
There are several well-established reasons to mulch! For gardeners, mulching is considered just as important as watering, feeding, fertilising, planting and pruning. And while weeding comes second to last place on our to do lists, it’s another tie first for importance when it comes to action in the garden!
Probably the most important use of mulch is that it to saves moisture and delays evaporation from around your plants. It does this by blocking sunlight and insulating the soil thusly acting as a buffer for the possible temperature swings with the crazy weather we get in a lot of places. Mulch saves plants nutrients by suppressing and even eliminating weeds for the most part, and it can continue to control them.
It can reduce soil ‘erosion’ and balcony splash caused by watering and ‘weather’ conditions and in many instances, here’s an important one, it can enrich and improve your soil (especially when natural mulches get mixed up with the top soil as it gradually breaks down). Mulch also reduces soil compacting after watering which leads to limited oxygen which could lead to unhappy roots. Mulch also makes the container soil earthworm friendly.
HOW TO MULCH
This answer is easy but bears a little thought anyway. It will also depend on what mulch you are using and for what reason. Stones are expensive so piling them up is a waste when a closely packed single layer will do the job and look right too. A general rule of thumb is mulch around 2 – 4 inches if you are using bark or wood chips, a covering layer and a half of peanut shells (as with any other nut shells or acorns or fir cones etc.) your eye and your container will guide you. To be effective, you need to use many more pine needles than bark. Its commonsensical you’ll see.
WHO NEEDS MULCH?
Every one and always! It just makes sense, saves a lot, helps a lot, looks good, enhances the containers and deck surrounds and just looks neat, tidy, very pretty and professional.
WHICH MULCHES ARE BEST?
This will depend a lot on the circumstances and the job to be done. The standard idea though is that mulch multitasks anyway so choose the one to suit the job at hand carefully. Many gardeners prefer organic mulches and other plant materials for obvious reasons. They are cheaper in many instances, some are eve home made like wood chips or grass cuttings, fall leaves and with some wet waste from the kitchen. They all protect from moisture loss, they can all moderate soil temps and most can beautify your container. Mulch may also protect your seedlings, and also protects the soil from early frosts and trespassing fingers wishing to check out the nearly all ripe strawberries.
And then there is their aesthetic value. Riff raff can define pathways and protect container-edge soil loss. Riff raff? Think of gravel on steroids! You’ve probably seen fist size sharp chunks of multicoloured, brown or grey stones in front of big houses or alongside water features or under concrete garden furniture. That’s riff raff. Municipalities use a lot of it for low maintenance fillers for traffic calming zones and street gardens.
Pebbles or garden stones on the other hand come in smooth rounds made so by water or mechanical tumbling. Next time you go to the garden centre, go to the stone and paving department and look ‘with new eyes’ as they say. You may be amazed at the choices you never knew you had before. The price may shock you though, but see, in our container world, we only need a little that goes a long way – with us less is definitely more.
Different coloured pebbles and stones can offset plants by highlighting beautiful leaves or whole plants as in cacti. From tiny stones chips to grey gravel to riverine pebbles to white stones to coloured semi-precious gems, all have a place.
WORKING WITH MULCH
When I have used organic mulches like bark or nut shells and so on, I tidy it up as and when (around every 4 – 6 weeks) by digging this in if I need to before I add a new layer – but well placed mulch even if organic does take a long time to break down. I also use garden netting which stops the heavier mulches from sinking into the soil. I cut it to the shape of the pot if needs be and place my mulch on top. Storing your organic mulches should be monitored carefully. They must be kept dry or may get mouldy and smelly and useless and therefore throwaway expensive. White stones I have used with cacti I smarten up by letting them lie in bleach, but over time they do colour and if I really must have white white stones then I replace them anew.
WATCHPOINTS WITH MULCH
Caveats include cold stones when over wintering that may affect roots, using diseased wood from prunings; using treated varnished or pesticide-sprayed wood chips, using plastic sheets at inappropriate times (stops air flow to roots), and even not using any mulch is not smart. Pine needles tend to make the soil acidic so watch that you plant acidic soil loving plants (like rhododendrons and blueberries) and lastly, grass cuttings used may mean an extra helping of nitrogen-rich fertiliser is necessary.
Marvellous mulch! What a wonderful service it offers any gardener and especially the container gardener as we see used for all sorts of rhymes and reasons. It saves time. It saves money. It saves nutrients from leaching. It looks good. It enhances. It’s easy to work with. That’s quite a list! Go mulching immediately – your containers will thank you.
OK. A question. Are you feeling mulched out? Yes? Good. Give yourself a gold star. See, you will not have to read this article again because the info will come back to you time after time ... when in your container garden; when at the garden centre or plant market; when visiting another garden and when attending the next garden club meeting you will see mulch where ever you go. Good gardening stuff I tell you. Smile now!
What do you want your container garden to do?
CASUAL VISITOR … and just browsing? Why not sign up to the Container Garden newsletter? It won’t matter what space or how many pots you have or even how much time you have to spend in your container garden; what will matter is that you get our reminders and good advice and ideas all in one interesting article.