Lambeth

Q – We’ve got asparagus frons in our allotment – how should we nurture them over the winter?

Pippa – Asparagus benefits from a winter mulch.  Look out for asparagus beetles and get rid of them before mulching.

Matt – The mulch will protect the crowns

Anne – Then keep them free from weeds

Q – My daughter would like to grow a cactus from seed.  Can you recommend a good variety?

Anne –  Rebutias or Mammillarias are good to go for because they are quite quick.  Get a free-draining seed compost, sow in spring and put it on the windowsill.  Another option would be Lithops (actually a succulent but great to grow).

Q – How long after the potato tops have died back can you leave them in the ground before lifting?  I’ve got ‘Charlotte’s’ and ‘Northumbria Delights’.

Pippa – No hard and fast rule.  Depends on slug population.  I try and lift asap because I have lots of slugs in my heavy clay soil.  ‘Charlotte’ potatoes don’t get slugs too badly, so I left them longer last year.

Matt – If you leave them they’re just taking up space when you could be planting something else

Anne – Some varieties change flavour the longer you leave them.  Worth experimenting a bit.

Q – When should you mulch an herbaceous border?

Pippa – Depends why you’re mulching.  I would do a bit in both winter and spring.

Matt – I would leave the stems on the top over winter and then cut that back and mulch just before they start to grow again

Pippa – Penstemon would benefit from a winter cover

Anne – Alstroemerias and Dahlias too.  But I would mainly do it in the spring.  I would only avoid if you were wanting to show off your Hellebores and Snowdrops.

Feature:

Sage

Hyssop

Lemon Verbena

Liriodendron

Magnolia

Q – What tree can you recommend for a 30ft (9.1m) square, enclosed, east-facing garden? It takes extremes of heat and gales.  It will be in a large raised bed. 

Matt – Arbutus unedo. 

Anne – I was thinking of Elaeagnus ‘Quicksilver’. 

Pippa – Tamarisk.  I might try an ornamental Hawthorn. 

Q – I am down-sizing to a roof terrace.  What fruit and vegetables can I grow?

Pippa – You can grow just about any vegetable in containers.  Peppers would be good.  Beans, carrots, beetroots, salad crops.  I wouldn’t try brassicas or sweetcorn.   45cm width and 45cm depth (18 x 18 inches) would be a good size container.

Anne – Try the French bean Jimenez.  Borlotti beans too.  The Shiraz Mangetout.  I would also try herbs like sage, thyme, rosemary and oregano.  Fresh mint in another bed.

Matt – Go for fresh-tasting crops.  Patio peaches and apricots would be good too.  Try Hestia in pots.

Q – I want to create a small wildlife pond in my garden.  Suggestions please. 

Anne – I’d put a liner in to get the sloping edges which will entice wildlife.

Matt – I’d go down to about 2ft (0.6m) and then go for native plants

Pippa – If you go down to 2ft (0.6m) then you’ll help avoid the water warming up in the summer and the ‘pea souper’ effect that afflicts a lot of shallow ponds.  Try and incorporate planting shelves to get different levels.

Q – Could you suggest plants for a balcony or for indoors that will help purify the air?

Pippa – Boston Fern and Spider plants

Anne – Peace lilies.  All indoor plants are good at removing indoor pollutants

Matt – Mother-in-Law’s Tongue. 

Anne – Get some containers and put a mixture of plants in.  For example, a Calathea, a Piggyback plant, and a fern.