Borders and weeds

Question

I am planning a border around our fence, which will be approximately 50m by 1m in total. As a test, I made a 2m by 1m test border, and planted malva, anemone, campanula, delphinium, lavender etc. On top of the bare soil between the young plants I've layed 70 litres of ornamental bark, to keep weeds out.

However, after a week or 2, there are already plenty of weeds coming through the bark. I'm also a bit confused about how the border plants will grow so they will fill up the border, when there's bark preventing plants to grow? That seems contradictive?

What is the advised way of setting up a border like this?

Answer 1

The trouble is, when you dig over soil to prepare for planting, there will inevitably be weed seeds in it, and those will germinate and grow now they've been brought nearer the surface, and through the bark. This assumes you dug out any obvious weeds and their roots prior to planting the bed. The only way to stop those coming through is to use a membrane and put the bark on top, but there is a big drawback or two with that method - the membrane does stop perennial plants like your campanula from spreading/increasing sideways, and weeds will still grow over time in the bark chips - seed will blow in and germinate and grow, even with a membrane beneath.

I would just like to say one thing about your plan to make a metre wide border all the way round your garden - I wouldn't recommend it. 1 metre is not deep enough to get a proper, layered effect using shrubs perennials and bulbs. It would be preferable to create a number of much wider (or deeper, if you like, from fence to outer edge) beds or planting areas, backing onto the fence, rather than a narrow border all the way around. When you create a planting area, its best to dig it over thoroughly, making sure you extract any roots and weeds you find, then emend it with some composted animal manure or your own good garden compost, if you make it. Once the area has settled, then you can plant, and always take into account the height, and particularly the spread, of any plants you choose, and leave enough room between plants for them to develop and grow properly. This is particularly important with shrubs. The space between them may look bare initially, but you can temporarily fill that by using annuals - nasturtium seeds, for instance, popped in between will give colour during summer and leaf cover while the permanent plants settle in and grow on.

After that, I recommend no mulch for the first couple of years (unless its very dry where you are and you want to keep the soil more moist) but do recommend the use of a hoe - hoeing over regularly when any weeds which appear are still small will effectively control weed growth. That is not possible to do if you have mulch, especially bark chips or stone.

As the plants grow on and get bigger, they will eventually fill up the space available, meaning less chance for weeds to grow, but for the first 2-3 years of new beds and planting, there will be plenty of weeds trying to grow. It gets less after that because you keep destroying them with your hoe before they get a chance to flower and set seed, or spread at the root.

UPDATE

In response to your comments. Take a look at this image here https://www.homesandproperty.co.uk/home-garden/gardening/win-a-500-shopping-spree-at-rhs-wisley-plant-centre-32278.html, just the image, ignore the rest. Its to give you an idea of what a deep planting bed can look like. What you plant in it and how close depends on which plants you choose, because growth habits differ. A plant like a Cordyline, or a small columnar tree such as Amelanchier 'Obelisk' for instance, doesn't take up much room sideways, but grows upwards and forms a trunk, whereas a low growing shrub like a lavender doesn't get tall and needs more room sideways and all round. Your delphiniums may get a bit wider, but tend to be taller, so growing next to those you might plant, say, a Spiraea Goldflame, and dot about Euonymus fortunei varieties for their evergreen, colourful leaves, with perennials in between.So the idea is to work out a combination of plants to use, not to dig one area 5 x 5 feet and plant one shrub in the middle. Not only would that be tedious to maintain, it wouldn't even look good... I wouldn't recommend Philadelphus particularly anyway, not for a mixed smallish border or bed, but even if you did plant a single Philadelphus in a 5 x 5 bed, you'd put ground hugging/ground covering plants around it - such as Campanula portenschlagiana, Ajuga, Oregano, Helianthemum and the like, depending on sun exposure.

Answer 2

I love Bamboo's answer. Just wanted to add this link I found...THIS is the only thing I have used or will use for edging between plant beds and lawns. A little trench. There is nothing better.

Your little plants are not happy mainly because of the bark. That stuff is NEWLY dead? Everything that dies has to decompose. The very next thing that happens seconds after death. The group that does this job are a vast array of bacteria, fungi, insects. They have to have readily available nitrogen for energy to do their job. The process of decomposition of raw bark chips sucks up what little nitrogen there is to be had in any soil. Soil doesn't come with the chemistry necessary for photosynthesis. Not enough for humans to be able to make their artificial gardens, food.

This video is made by...a company I do not trust but this is how I've always made the edges of lawns (which is what the eye sees as long as the color and texture of the lawn is somewhat uniform). So easy. No need for concrete, plastic edging. edging a lawn between plant beds

That mulch is disgusting but this video shows how I've made edges for 'half a century'...love saying that. These trenches need to be maintained once a year using that same shovel, throwing the soil that has filled the trench back onto the top of the bed. This should be done when planning a new mulch install. Do before the mulch is installed.

Go check to see if your municipalities offer human poo and sawdust mulch. This is the ONLY mulch I would use and yes, at first it took some doing to get clients to make the leap. They were blown away, my crews were blown away, I was blown away, absolutely perfect fine fine texture dark taupe color no sticks no stones no weedseeds and no pesticide residue. SMELLS wonderful. Not at all the same composition at all. Thoroughly decomposed and tested FIVE times before allowed to be sold to the public. Check it out.

Also, there should be 2" minimum air space between the bottom of your fence and any soil, weeds or mulch. Or you'll be replacing your fence sooner than later.

I'll add a visual of 'plant beds' and lawn, sweeping consistent radius curves using those little trenches...notice the peninsula of plant bed cutting off the view of the entire lawn. THAT is professional. Makes your yard more mysterious, more usable. You do not want to see your entire back yard at one glance from your back yard. Ditto for the front.