Tony Dickerson problem solves
Q How can we get rid of celandines in our garden? Linda Schofield, Allithwaite, Cumbria A Lesser celandine ( Ranunculus ficaria) appear above ground in late February and die back in late April. They are pretty, but spread easily and can take over. Control is difficult due to the short growing season and the persistence of the root tubers. Digging them out is usually not successful as you’ll end up scattering the tiny tubers and each will grow into a new plant. Mulching to a depth of at least 10cm (4in) may help but is unlikely to solve the problem.
Spraying with a glyphosatebased weedkiller may be your only option to get rid of this tenacious wildflower. As it’s difficult to apply weedkillers around other garden plants, I’d lift those, washing their roots to ensure I wasn’t moving any celandine. Then I‘d plant them out in either a new permanent bed or a temporary holding bed. This will allow spraying in late March or early April and repeat treatments each spring for another two or three years until I was certain the celandine had been totally exterminated. Personally, however, I think the best policy is to plant up densely and ignore the problem as by early summer there’s usually little sign of them.
A ‘live and let live’ philosophy may be fine with celandine, but now is a crucial time for weed control elsewhere in the garden. From spring through to late autumn, timely hoeing of weed seedlings as they germinate throughout the growing season will considerably reduce the time spent on more substantial weeding later.
In the vegetable garden, and on unplanted ground, put down a sheet of black polythene or woven weed fabric so that nothing will germinate or grow beneath it. When it has done its job, roll back the sheet to plant.
Mulching won’t help get rid of tough perennial weeds such as thistles or nettles, though, so spray vigorous weeds such as these with a systemic, glyphosate-based weedkiller in early June. It’ll be carried down into the roots and, over a period of three weeks or so, should give pretty good control.
Q When can we expect our jade plant to flower? Hayley Bunting, New Milton, Hampshire
A The jade plant, also known as the money or friendship tree ( Crassula ovata), is a great houseplant, tolerating a good deal of abuse. Young plants flower once a framework of woodier stems has established, and then benefit from a bit of TLC to encourage them to reliably flower.
Originating from South Africa, the plant won’t flower in dull conditions so position in bright light, such as a sunny windowsill. Compost should be quite gritty and loam-based, so use cactus compost or modified John Innes No 1.
Repot young plants when the pot is well-filled with roots, usually at two or three year intervals. Older plants seldom need re-potting. Water gently in spring and summer, and liquid feed with phostrogen or Miracle Gro all purpose fertiliser. Water sparingly in winter and aim for a temperature between 45-55F (7-13C). Q Why is our lawn covered in moss? Joan Fisher, London
A Moss has a competitive advantage over grass from late autumn through to spring, as it will grow when temperatures are too low for the grass. Steps to repair the lawn can be taken in the spring, once the weather is warming and the grass growing.
First, rake the lawn to remove debris and the worst of the moss, or use a mechanical scarifier on a light setting for larger areas. Apply a moss killer that contains ferrous sulphate, following the manufacturer’s instructions, ideally using a distributor to get an even application. When the moss turns black rake it out and follow with a summer lawn feed. Or, simply apply organic fertiliser Mo Bacter, which digests moss over a period of several weeks.
Moss problems can be reduced by aerating your lawn, keeping it well fed and avoiding mowing the grass too short. Q What can we do with our waterlogged new lawn? Chris Deakin, Bakewell, Derbyshire
A After a reasonably dry start to last winter, many areas have had a lot of rain since January and turf grasses won’t tolerate waterlogging for long. If properly prepared, lawns will have some resilience, but I’d excavate a small inspection pit to a spade depth to check for compaction. Fill the pit with water and leave 24 hours to observe. If the water doesn’t drain away, you’ve got a problem with compaction and the lawn may have to be re-laid. A lawnawn is really only as good asa the preparation that has gone into it. There are no short cuts.
I like to dig over the area with a spade, then gently tread and rake level. Over six weeks the ground will settle further, so tread and rake two or three times more using a scaffold board edge-ways on to get the level. On permanently wet soils, lawns can be laid over a sand-bed: a layer of at least 10cm (4in) of sharp sand over a properly prepared soil. The sand provides good drainage but grass roots can grow 20cm (8in) or more down into the soil to access moisture.
Q What has killed our ivy? Greta Ward, Hayling Island, Hampshire A It’s normally quite difficult to kill off ivy and the run of mild winters over the last 10 years has seen it flourish in the countryside and gardens. However, it looks as though yours has suffered from a root disease. Ivy is moderately susceptible to both honey fungus and phytophthora.
If it’s honey fungus, scrape the bark on thicker stems at soil level and you’ll see fungal flecks beneath. If it’s phytophthora (also known as root rot) you’ll see blackened roots that fall apart when you dig up plants. Q I garden organically. Are all manures organic? Grant Collins, by email A ’Organic’ means derived from living matter so, by that definition, manures consisting of the droppings, urine and bedding (straw or wood shavings) are all organic.
Some individuals and organisations would be concerned about the medication used on animals (such as antibiotics) and pesticides applied to the crops prior to harvesting for straw and not regard them as truly ‘organic’. Stables and farms may be able to assure you about these matters.
Most soils, especially in urban areas, are low in organic matter, while the soil community of microbes is very efficient at breaking down ‘contaminants’ so, on balance, as an organic grower myself, I happily get manure from any source I can.