Weeds, mulching and clematis

IMGP1863The warmer temperatures and rain have combined to produce a lovely crop of annual and perennial weed seedlings. I usually wait until I can identify the insurgents before removing them as I encourage some self-seeding such as forget-me-nots, nigella and foxgloves.

Perennial weeds
This year I am determined to get my best, south-facing border under strict control as it has been plagued by alkanet, a member of the anchusa family. It is a tallish, very hairy-leaved, evergreen plant which has pretty bright blue, forget-me-knot-like flowers in spring. It is drought-resistant, disease-resistant, pest-resistant ie no b…ger wants to eat it. So it sounds the perfect plant? It is if all you want to grow is alkanet. I have never known a plant that is so good at colonising. It spreads by seed, of which it produces thousands – and every single one seems to germinate. It is perennial and if left alone produces a monster tap root that would rival the horseradish and has a knack of spreading its stems sideways to kill off any more delicate opposition. If you fail to dig out all its root, it will relentlessly pop up again. To me, it is up there with Japanese Knot Weed – OK maybe that is a bit extreme – but you can probably tell I am not a fan. I have a few plants of it in my garden which have grown between paving cracks or right next to, say, a rose bush so I cannot remove it; I tolerate the flowers ( which are quite attractive) until I see them fading and whip them off before they seed, then cut off all growth and regrowth throughout the year – but it still cheerfully pops up again. There is a new ‘spot-on’ gel weed killer from Roundup which I might use this year but I try to garden organically so am a bit reluctant to use the heavy guns, ie glyphosate, but according to their video you just dab one leaf and the plant keels over, hmmm if that works on the alkanet I shall be seriously frightened of this product – it will be up there with Agent Orange.

Bark mulches
So, having done my best to remove all nasties by digging and hoeing, I am covering the bare soil with a bark mulch – about 2 inches deep. This will have several uses: suppressing weed seedlings – any that manage to grow through the bark will be easy to spot and remove – retaining moisture in this dry border and it seems to deter cats. As I hoed, my two cats sat watching, thinking Yay! New toilets! And of course as soon as my back was turned, they started scratching with enthusiasm. However, once I had applied the bark I noticed it was untouched – so far. I am hoping that this tactic will save work and save plants too; I lost a few from this border in last year’s hot summer. I will keep you posted on whether it is a success and how long it lasts.

Gravel-covered beds
Following on from mulching I thought I would share another weed suppressing tactic. It is a bit extreme but it suits this site. I inherited a largish front raised sunny border which was wild with overgrown shrubs such as rosemary, cistus, berberis, and bamboo. I realised that it would make a good seating area as it saw sun for most of the day and decided on radical action: I dug up the lot. I spared a yukka and a pretty dwarf apple tree which gave good Cox’s orange-type fruit. I admit it was very hard work; the bamboo was the most difficult to remove as tough rhizomes spread downwards and sideways in seemingly endless runs; but it was very satisfying to see a clean open space which looked so much bigger once all the shrubs were gone. I then covered the area with two layers of heavy-duty landscaping fabric and three inches of shingle. So I now added a bench, some cobbles and shells and the area became my beach. The ‘beach’ effect was somewhat spoilt by the apple tree but I couldn’t bring myself to axe this for the sake of the theme. There was dwarf bamboo at the front of the bed which abutted the retaining wall and this has regrown in places but only where the fabric meets the wall but nothing has grown through the suppressing layers. As an experiment I scattered some nigella seeds into the gravel and was surprised to see very sturdy seedlings emerge which are only rooted in the gravel – almost growing hydroponically.

I have never had much luck with clematis, they either get killed off by harsh winters, pests or wilt. The early-flowering montanas are an exception, the only thing they don’t like is harsh pruning. I thought I would have another go with a viticella: Black Prince. These clematis have a scrambling habit, similar to the montanas. so are good for planting near trees. They are reputed to be tough, enduring cold winters, and, best of all, apparently do not suffer from wilt. It is alleged that the viticella will flower from June until September. They can be grown in pots so I have planted one in a glazed pot next to the Penny Lane rose in the hope that it will scramble over the porch; it is already making good growth in the three weeks since planting – two shoots were munched off straightaway by snails but since scattering slug pellets in the pot it has been untouched. I hate using the pellets but at least they are contained in a pot amongst the pebbles that I used to stop the soil baking in the sun.

Wallflowers and erysimums
I have just pulled up the last of the wallflowers. They are among my favourite flowers – they are so easy – I just buy a bundle of young plants in the autumn from garden centre or market and dot them around with the tulips; I love their heady scent and messy blooms of rich reds, burnt orange and bronze. Before pulling them all up I check the growth of the best: if they are shooting beneath the flower stems, and I have room to keep them, I shear them off to low shoots, give them a feed and have often been rewarded with handsome bushy plants next year which flower early.
If you fancy seeing wallflowers blooming throughout the year, try planting erysimums – a perennial type of wallflower which, although does not have much scent, it will give bursts of colour throughout the growing season. I have a Bowles Mauve (photo above) which is three years old and is currently looking good. Thompson and Morgan have a lovely variety called Winter Sorbet which starts purple and turns burnt orange as the bloom matures. I found a pure burnt orange coloured erysimum for a couple of pounds in the local market and it is currently lighting up a dull corner of a border. These plants seem to happily tolerate poor soil, drought, deluges and no pests like them – I must buy more.