Thompson & Morgan
Facebook Q&A Session 21st March 2014

Thompson & Morgan Facebook Q&A Session 24th January 2014
- Your horticultural questions answered.

Questions and answers
  • Andy Brown
  • In the school gardens we don't have room to plant potatoes in our beds. We are going to use Potato growing bags. Our compost bins are still too young to produce any compost as yet so can you advise what is the best compost to use? Also a sneaky second question - can we "companion" plant potatoes with anything? Many thanks in advance.

  • Sue - T&M Horticultural Expert
    Sue Sanderson - T & M Horticulturalist
  • Hello Andy, a good quality multi-purpose compost is best to use for growing potatoes in containers. The light, airy structure is perfect for easy root growth and tuber formation. When growing potatoes in bags and containers it’s best to feed them every other week with a balanced liquid fertiliser or work in some slow-release potato fertiliser before planting for the highest tuber production. Ordinary multi-purpose compost generally only has enough nutrients to keep plants happy for 6 weeks.

    With regards to companion planting, I can't recall any specific companion plants for potatoes as they mainly suffer from fungal and bacterial diseases. However, the principle of growing herbs, and encouraging insects and birds into the garden is still a good one to follow as it encourages a healthy garden. Take a look at our Companion Planting Guide for some ideas. You could even grow mint as an accompaniment to the finished crops! I hope this gives you some ideas Andy, best of luck.

  • Clare Rushton
  • honesty seedlingsThis may be a really stupid question but I'm not sure what they are. I planted thousand of poppy seeds last year, are these young poppy plants or stinging nettles coming through?

  • Sue - T&M Horticultural Expert
    Sue Sanderson - T & M Horticulturalist
  • Hello Clare, don’t worry these definitely aren’t stinging nettles. They look like Honesty (Lunaria annua), a hardy biennial plant which makes a rosette of leaves in the summer and autumn before flowering in the spring. Much like forget-me-nots, they have a weedy nature but are often cultivated in gardens for their colourful show of spring flowers. Honesty also has attractive flattened seed pods which look like coins, and the flowers are an excellent source of nectar for early butterflies. The largest plants in your photo will probably flower this spring. I hope this helps.

  • Annie Polgara
  • (first timer question) I sowed sweet peas into those cardboard like pots (tiny) and they have grown really big - do I leave them in the cardboard pots when I re-pot them and how big a pot do I pot them up into? When can they go into the garden?

  • Sue - T&M Horticultural Expert
    Sue Sanderson - T & M Horticulturalist
  • Hi Annie, in theory you are supposed to be able to leave plants in cardboard (or coir fibre or peat) pots and roots should grow through. However this isn’t always successful and the cardboard can become a barrier to the roots, resulting in slow growth. You could either completely remove the plants from their pots and re-pot them or make sure the bottom of the cardboard pot is removed to allow for root growth. Tearing away the top of the pot will also help, or planting deeply enough that the top is completely below soil level. Wetting the pot will make tearing easier.

    Sweet peas are normally sown in deep pots as they are deep rooting and then planted straight out into the garden once ready. To pot up into bigger containers, choose a pot which is about 5cm (2") bigger in diameter than the original pots. To stop your sweet peas falling over or becoming tangled its good practise to pinch them out just above a set of leaves to promote bushier growth. This will also delay growth if the weather is unfavourable for planting. Sweet peas are hardy annuals so can be planted out from mid to late spring once the weather has reliably started to warm up. If they’ve been raised indoors in a warm environment then its best to harden them off for a week by putting them outside during the day and bringing them in at night. If we are still having regular frosts then wait until milder weather before planting out. You can find out more about growing sweet peas with our 'How to grow sweet peas' guide. I hope this helps Annie, let us know how you get on.

  • Santosh Rana
  • I emptied a large compost bin which had top soil - however I did not find any worms. Does this mean the soil is unhealthy?

  • Sue - T&M Horticultural Expert
    Sue Sanderson - T & M Horticulturalist
  • Hi Santosh, this is nothing to worry about. Worms will only be present in soil if there is a supply of organic matter for them to eat, such as dead leaves, decaying plant material or manure. I’m also not sure if your compost bin is sitting on the ground with easy access for worms or whether it is raised up on feet. The soil in the compost bin could have lacked organic matter or it may have become too saturated with water or too dry for worms to be happy. Also if it has been in there for a while there could be a lack of oxygen in the soil. Once the topsoil is spread back out in the open many creatures should start to inhabit it again. You can help improve your soil by digging in lots of organic matter such as well rotted manure or compost. I hope this helps.