Thompson & Morgan
Facebook Q&A Session 4th February

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Name: Hazel Jonker Clifton

Question: Hi Sue, is now a good time to divide my Miscanthus sinensis Zebrinus grass plant? Thanks a lot.

Answer: Hi Hazel, what a lovely grass to have in your garden! It would be best to wait until your Miscanthus starts to put on new growth in the spring. Keep your divisions as large as possible (no less than 15cm). If you want smaller pieces then it’s best to pot them up in some compost and grow them on before planting back out in the garden. The larger the divisions, the quicker your plants will re-establish themselves.


Name: Benny Lau

Question: Hi, im having a problem with my romanesco veronica. As u can see through my attached picture, it grows leaves on the head. what did i do wrong? thx a lot

Answer: Hi Benny, this is quite a common problem with cauliflowers caused by heat and /or dryness in the soil at the time the heads are forming. When growing cauliflowers, make sure you keep the soil moist, especially during hot weather, to try and reduce the stress on the plant.


Name:Kerry Middleton

Question: I want to start a raised veg garden this year but struggling on where to start, can i use broken down wooden pallet's for the frame and what do you recommend i use for soil?? i want to grow runner beans, carrots, salad crops & new potatoes for summer then go to old potatoes for winter - HELP....

Answer: Hi Kerry, broken-up wooden pallets would be fine to use for a frame – I’ve seen people use all sorts of reclaimed wood for their raised beds! Though you may want to treat them with a wood preservative to prevent them rotting. When you build your raised beds make sure that the centre is within arm’s reach from all sides; this reduces the need to tread on the soil and prevents compaction.

With regards to the soil I would use ordinary garden soil and incorporate plenty of compost, well rotted manure or recycled green waste. Depending on how big your raised beds are you may need to import some additional topsoil from another source to fill them completely.

All of the vegetables you’ve mentioned will thrive in raised beds. You mentioned growing new potatoes followed by ‘old potatoes’ - I assume by old potatoes you mean maincrop potatoes. Both types need to be planted by May at the latest so they will occupy the ground at the same time.

If you’d like Christmas-cropping potatoes (new or salad potatoes which mature in December) then these are planted in August/September so could occupy the ground after your new potatoes have finished. Christmas-cropping potatoes do require protection from frost to be successful however, so you may prefer to grow them in patio bags in a frost free position. Good luck with your vegetable garden Kerry, let us know how you get on.


Name: Deirdre Snook

Question: I really need to clear some of the straggly plants & green up the garden with structural plants so it looks good in winter too. Just not sure where to start with a good green background ... perhaps some advice on what shrubs look good all year round, grow tallish (6-8 feet) and do not spread too much ....

Answer: Hi Deirdre, there are many shrubs to choose from but it sounds like you would benefit from medium-sized evergreen shrubs as they will provide a background all year round and may provide attractive flowers or berries too. If you have acid soil then Camellias would be ideal with their attractive dark foliage and colourful summer flowers. If you’re unsure of your soil type then you could try these evergreen shrubs:

  • Garrya elliptica  (Silk-tassel bush) which produces long decorative catkins in winter and early spring (make sure you purchase a male plant such as ‘James Roof’ or ‘Evie')
  • Eleagnus which provides a range of different evergreen leaf colours.
  • Cotoneaster lacteus which has white flowers in the summer followed by red berries which will persist over winter (birds find them unpalatable)
  • Pyracantha which are useful as wall shrubs due to their arching habit but can be grown as free-standing shrubs as well. They have white flowers in the spring followed by masses of berries (yellows, oranges and reds depending on variety) which persist into the autumn.
  • Osmanthus x burkwoodii which has small leathery leaves and fragrant white flowers in late spring.
  • Daphne bholua ‘Jacqueline Postill’ which has intensely fragrant pink flowers in late winter
  • Viburnum tinus which are great for dense leaves and winter flowers.

I hope this has given you a few ideas to start with!


Name: Beth Stewart

Question: I hope to plant a woodland area. Last year I planted some native trees which I now want to underplant with woodland flowers. Any ideas please?

Answer: Hi Beth, there are a variety of plants which will thrive in woodland conditions. Bulbous plants such as Snowdrops, Winter Aconite, Bluebells and Lily of the Valley love the shady, moist conditions that tree cover can provide. Perennials such as Geranium himalayense ‘Birch Double’, Phlox divaricata make an attractive ground cover and will bring summer flowers to your woodland garden. For lighter, dappled shade will thrive and create masses of pretty lavender-blue flowers.

Dappled shade is also ideal for Hellebores, Dicentra (Bleeding Hearts), Meconopsis (Himalayan Poppy) and Alchemilla mollis. One of my favourite woodland plants is Brunnera, which can vary in leaf colour (there are variegated forms and plain green) and produce dainty blue flowers in April and May (much like a Forget-me-not) Or you could try Tiarella cordifolia (Foam flower) which have frothy flowers in the summer. There are so many more woodland plants than I can mention here but I hope that gives you a good start! Good luck Beth.


Name: Sarah Griffiths

Question: We moved into our new house last summer and after installing my first ever greenhouse I am looking forward to sowing seeds for the first time, I also want to cut out some of the lawn and start a cottage garden effect - my garden is south facing and gets very hot, any tips on what sort of cottage garden flowers will work best? Thanks.

Answer: Hi Sarah. If you have a south facing garden then make sure that you choose plants that enjoy a position in full sun. Try this link for some inspiration.

Make sure that you prepare the soil well before planting by digging in plenty of compost, well rotted manure or other organic matter. Following planting, it would also be well worth mulching your border with gravel or bark chips after a good rainfall while soil is still moist. Good preparation will help to retain moisture in the soil and cool the roots during the hot summer ahead.

If your garden is particularly hot and dry then it is worth selecting plants that are adapted to these conditions. Those with furry or silver foliage such as stachys and Helianthemum deflect the sun’s rays to prevent their leaves from scorching. Many aromatic plants such as rosemary and lavender are also well adapted with tiny leaves to reduce evaporation. Succulent plants store water in their fleshy leaves – try Sedum ‘Turkish Delight’ for its stunning burgundy colour. Rhizomatous plants such as bearded iris also enjoy baking in a hot sunny spot. Hope that gives you some ideas Sarah.


Name: Sarah Griffiths

Question: Hi, have a question for Sue's next Q&A session. When is the right time to prune back passion flower? We planted out two plants this summer and they did really well but are looking a bit weathered and pathetic due to recent weather, do we leave them as they are or attempt to prune back to tidy up?

Answer: Pruning passionflowers is best undertaken in the spring. Start by pruning out any dead or damaged shoots, then reduce the remaining stems to fit the growth to the available space, forming a framework which should be tied in to its supports with soft ties.
After flowering, cut back any flowered shoots to two buds away from the previous year’s framework of stems. Try not to prune any harder than this as hard pruning may forfeit any flowers in the following year.


Name: Lucy Garden

Question: A question for Sue, please - I planted a hazel nut shrub 4 years ago and have just seen my first catkins. I was excited that I might get my first nuts, but then I read that I'll need a pollinator of a different variety. Is this right? What should I do? I don't remember which variety this one is, and don't want to wait a further 4 years for the pollinating bush to mature, even if I could be sure it was a different sort and could make room in the garden for it...

Answer: Hi Lucy. I’m afraid it’s true - hazels do crop better if they are pollinated by another variety. But if there are hazels growing in nearby hedgerows then these should be capable of doing the job. However if there are no other hazels about then you will need a pollinator to get a good crop.

If this is the first year that you have had catkins then I would suggest that you wait and see what happens in the coming season. There may be pollinators in nearby gardens that you haven’t spotted. You will need to net the tree if the catkins are pollinated as you are likely to have some stiff competition for the hazel nuts from local squirrels.
If you decide to invest in another hazel but are unsure which variety you have, then choose one that is distinctly different, such as a purple leaved or contorted variety.


Name: Keith Gowland

Question: The local chimney sweep said that soot was good for spreading on the garden, high in Nitrogen and helped keep slugs at bay.
would you recommend adding soot to soil? if so , what amount per m2?

Answer: Hi Keith. This is a fascinating question as the use of soot in the garden was quite a common practice in years gone by but has lessened now since homes have central heating. Soot makes a useful soil conditioner and also contains a small amount of nitrogen to feed your plants. It darkens the soil, and it is said that this causes a warming effect by absorbing the sun more readily. I have read that it makes an excellent insecticide and soil fumigant too, particularly if mixed with lime, though I am not certain what ratios should be used. If used as a top dressing it is an excellent slug deterrent but it will need reapplying after rainfalls.

However, there is one very important point to note - fresh soot is too caustic to put on the garden straight away and must be stored in a dry shed or similar dry location for at least six months before you use it. You can use it as a top dressing (roughly 200g per square metre) or just spread it around plants to deter slugs.


Name: Calum Wiley

Question: I've also got a few Fuchsias and Geraniums on order, so the idea is to put all in pots, fix trellis to my house wall and shed wall and hang/tie the pots from the trellis. At the moment I'm pondering using terracotta pots (which I can paint) or plastic pots. What size of pots should I consider in using, as I am thinking... 5" or 6" but the depths of these pots seem to me as being shallow at 3" to 3.5"? Also, when I take delivery of these plants, should I pot them into 2" pots and should I put in bone meal or anything like that at this stage? Cheers in advance and sorry for any spelling mistakes :) Cal

Answer: Hi Calum.  I am assuming that you have ordered plug plants. When you receive them, pot them into 7.5cm (3”) pots using good quality compost and grow them on in warm, bright, frost free conditions. You don’t need to add anything at this stage. Once they are well grown and have a good root system you can ‘pot them on’ into their final containers. At this point you should add a slow release fertiliser and some water retaining granules.

You can use terracotta or plastic pots, however terracotta is porous so the soil will dry out quicker than in plastic pots, and they are also much heavier – particularly after watering! The pots that you are describing do sound a bit shallow. Wide, shallow containers have a large surface area which increases water loss through evaporation, so you will have a constant battle to keep the compost moist in a small, shallow pot. Personally I would use something deeper as the plants are likely to outgrow your pots quite quickly.


Name: Calum Wiley

Question: I've got Begonias bulbs, and on order I have Dahlias, Gladiolus, Lilies, Cala Lilies. When do I start these off, as I've seen on Gardeners World and Carol Klein that they start them off now in trays and even cut some in pieces when they've sprouted. Should I start mine off now and straight away when I get the rest and will I need to use my propagator for this as I'll be using it for my seeds? I want to plant mine in pots and just put the pots into the planters when the plants are ready to go out, as I'd like to lift the pots out and store them for the following year. So what size of pots do I need to do this?

Answer: You can start off the begonia tubers during the next few weeks and the other plants when they arrive. You don’t need to put them in a propagator but they will need to be kept in a bright, frost free position such as a greenhouse or conservatory until the weather warms up.
With regard to the pot size, it really depends on the size of each bulb or tuber. Dahlias and Lilies can be quite large and will need reasonably deep pots from the start, whereas begonias can be started in smaller pots and then repotted later on in the season. You may want to pot up the calla lilies and gladiolus in small groups rather than individually for greater impact which will, of course, require a slightly larger pot.


Name: Craig Mason

Question: I have some bare root raspberry cane's 3 autumn bliss & 3 malling promise can i grow these in pots on my patio instead of planting in the garden.

Answer: Hi Craig. As the name suggests, Autumn Bliss is an Autumn fruiting variety. Autumn fruiting raspberries produce short, stiff growth which doesn’t require supporting, so they can easily be grown in containers. You can prune all Autumn fruiting raspberry canes to ground level each February.

Malling Promise is a Summer fruiting variety and the spreading stems will require support. These are best planted in the garden. Before planting, prepare a framework of wires stretched horizontally between two sturdy 1.8m (6’) posts. Plant raspberry canes in a row against the wire supports, allowing a distance of 60cm (24”) between plants. Loosely tie the stems of summer fruiting raspberries in to their support wires as they grow. The canes should be pruned to 15cm (6”) above ground level immediately after planting to encourage more shoots to be produced.
In autumn, prune the canes which have fruited over summer to ground level. Canes which have not fruited should be ‘tied in’ to their supports. Aim to have 6 to 8 fruiting canes per plant. Hope this helps Craig.


Name: Ann Norfolk

Question: I recieved my polyanthus tuberose this morning, please can you tell me do i pull the small bulbils off and plant them or just plant the bulb. The reason is i bought some last year from Parkers and all i got was one bulb no bulbils i had the most beautiful flowers. There was 5 bulbs in total. I have been reading that you take the bulbils off and they won’t flower for a couple of years till the bulb gets bigger hope you can help Ann

Answer: Hi Ann. You are quite right. If you remove the small bulbils and pot them up they will produce new plants which should be of flowering size in a couple of years.

Polianthes tuberosa requires a minimum temperature of 15°C (59°F). Plant tubers in containers at a depth of 10cm (4”) and grow them on until large enough to move outdoors when all risk of frost has passed. When growing tuberose in extremely mild areas, you can plant them directly into moist, fertile, well drained soil in sheltered sunny borders.

With the first autumn frosts, lift clumps of tubers from their growing positions. Keep any young offsets and tubers which have not yet flowered and discard the older portions which have flowered during the summer as these are unlikely to bloom again. Store them over winter in peat or sand, in a cool but frost free position, then replant tubers of Polianthes tuberosa the following spring. If you do this every year then you will have a constant supply of new plants to replace the older tubers which have flowered.