Thompson & Morgan
Facebook Q&A Session 15th November 2013

 

Thompson & Morgan Facebook Q&A Session 15th November 2013 - Your horticultural questions answered.


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Name: Julia Rhodes

Question: I've got some overgrown - I think - rose bushes in the garden and want them to be more under control and better producing / looking next season. Is it a good idea to prune them right back, and if yes how far back and where do I cut the branches? Many thanks in anticipation. JR

Answer: Hi Julia, bush roses fall under three main types – hybrid tea, floribunda and shrub roses. Hybrid tea roses produce large flowers, either singly or in threes at the tips of stems. Floribunda roses generally produce clusters of small flowers at the tips of stems - each flower within the cluster opens at different times. Shrub roses generally have large growing habits and very thorny stems. All can be cut back quite hard if required. Hybrid teas and floribundas flower on new wood so can be cut back hard each winter, to within 15cm (6”) of the base for hybrid teas and 30cm (12”) of the base for floribundas. Shrub roses flower on wood which is 2 or more years old so are only lightly pruned to maintain a good shape. You can cut them back hard but you may lose flowers for a few years. The best method of pruning these roses is to gradually prune out the oldest stems to ground level, removing up to a third each year. This will encourage vigorous new growth and rejuvenation without losing all the flowers. All roses are best pruned in February or March, provided we’re not experiencing severe weather. Pruning cuts should always be made just above a bud, at an angle away from the bud. I hope this helps Julia, best of luck with your roses!


Name: Lyndsey Gibson

Question: How do I store lily bulbs over the winter? Can I plant them into containers and store them in the shed? Your help would be much appreciated.

Answer: Hi Lyndsey, if your lilies are growing in well-drained borders there is no need to lift them as they are fully hardy. However, if you have heavy clay soil then it probably is a good idea to lift and store them over winter in case of rotting. Lilies grown in containers can also be left outside – I tend to group mine in a sheltered part of the garden, but you can also bubble-wrap the outside of the pots to offer some insulation. Lilies will grow new roots in the autumn and winter during mild weather so it is beneficial to leave them in place for the best growth and flowering next year. It’s certainly not too late to plant lily bulbs now – if planted in pots they can be left outside as mentioned above. However, if you do need to lift and store them, carefully clean the bulbs and trim the roots. Lay them out on a tray for a day or two to properly dry out – this helps prevent fungal infections taking hold in storage. Then place them in a paper bag and keep somewhere very cool and dry, such as a shed or garage, until spring. I hope this helps Lyndsey.


Name: Sarah Jackson

Question: Should I be cutting back the foliage on: Bearded Irises, Euphorbia purpurea and Pulmonaria? Would welcome your advice!

Answer: Hi Sarah, bearded iris can have their foliage cut back as its starts to brown. If the foliage is green, the plant may still be making use of it, or withdrawing nutrients back into the rhizome in preparation for dormancy. It has been quite mild so far this autumn but it looks like frosts are on their way so you should shortly be able to cut the foliage back. Euphorbia ‘Purpurea’ and Pulmonaria are evergreen or semi-evergreen perennials. You can cut back the old, flowered stems on the Euphorbia, but take care to leave any of the new shoots intact as they will bear next year’s flowers (remember to wear gloves!). Pulmonaria generally just need the old leaves removing in summer after flowering but can be cut right back now to tidy the plant up, cutting almost to ground level. I hope this helps Sarah.


Name: Deborah Mayne

Question: Please could you give me some advice on over wintering my geraniums, which are now looking very dejected after being planted far too late to achieve anything this summer! Many thanks, Deborah Mayne.

Answer: Hi Deborah, bedding geraniums (Pelargoniums) can be successfully over-wintered provided they’re kept frost-free. If they’re planted in the ground you will need to gently dig them up, taking as much of the root ball as you can, and replant them into pots of multipurpose compost. Check the underside of the leaves for pests and treat any infestation as soon as possible, as they will quickly multiply once under cover. Water the plants and place them in a bright, cool (but frost-free) greenhouse or conservatory. A cool windowsill would also be fine. The secret to over-wintering Pelargoniums is to keep the compost almost dry during winter as they are very susceptible to rotting in cool conditions. You can plant them out again after the risk of frost has passed in May next year. I hope this helps, good luck.