Q&A with gardener and horticulturist Phil McCann

Phil McCannBack by popular demand, gardening guru Phil McCann from the Royal Horticultural Society (RHS) paid us a return visit in October 2010 to offer tips on everything you need to know about gardening, with a special emphasis on growing your own fruit and veg, from what to plant to how to plant it, and everything in between.

Phil was previously assistant producer on BBC's Gardeners' World, is a trained horticulturist, a gardening journalist and a member of the RHS Vegetable Trials Committee. The RHS is the UK's leading gardening charity. Free one-to-one gardening advice is one of the many benefits of an RHS membership

Phil's first MN Q&A took place in June 2010 and you can read it here.

Fruit, vegetables and herbs | Weeds | Difficult growing conditions | Flowers, trees and hedges | Lawns


Fruit, vegetables and herbs

Q. bobs: What is the easiest or best way to dry chillies?

A. Phil: To dry chillies, I would recommend you thread them together and hang them in a dry, light, frost-free airy space. A cold greenhouse is great but anywhere out of the reach of people and animals. 

Q. Iamcountingto3: Any recommendations for genuinely beautiful vegetables that I could grow in containers that would fit with a 'holiday vibe' that I'm trying to create in my garden? I have Mediterranean-style herbs already. 

A. Phil: For holiday-vibe veg, it's got to be Swiss chard. It is gorgeous and truly beautiful. The red, orange, yellow or white stems are so colourful and the leaves that bobbly healthy green you want from a veg. It's easy to grow from seed, and I have to admit I fancy some in my new cottage garden front garden. I also love the ferny leaves of carrots (which, again, is planned into my new front garden) as it reminds me of the grassy growth on many sand dunes.

Q. Iamcountingto3: Now, Swiss chard is very pretty. But I always assume it's going to taste like the perpetual spinach I remember with horror from my childhood. Is it a vegetable likely to terrify (reasonably veg-friendly) small children? Be honest now!

A. Phil: I actually think Swiss chard is tasty and if you do a little prep it can be a real success. I always remove about a third of the lower part of the stem as this can be tough. Then cut the remaining stems (or major ribs) into chunky sections and stir fry them. The leaves need to be steamed to keep the vitamins and taste and prevent that mushy quagmire effect - works for me! Oh, and always clean the leaves well as grit doesn't go down well. 

Q. moonfacemama: I have a brown turkey fig in a large pot in our sheltered south facing back yard (in t'north). It started looking really sad in late summer but perked up after some random stinking homemade nettle plant food. What can I do now to ensure it comes back in the spring?

A. Phil: It should be fine. They are quite tough but don't be overbearing generous with the soil they grow in - now it will - hurrah! In fact, restrict root growth, not repotting too often. Too much root room equals loads of leaf growth and no figs. Lets hope it doesn't get too cold this winter. And you are right about nettle juice - I haven't smelled anything like it since... I won't go on!

Q. bobs: I have been growing carrots for the last few years and even with the best soil condition I can give (raised link-a-bord beds, light soil not recently manured etc) they only seem to grow really small and take ages. Which varieties do you recommend for a decent size?

Gardening children

A. Phil: It seems strange you haven't had a good crop. Are you giving them long enough to grow? Are you watering in dry spells? Sow in April and May and maybe go for New Red Intermediate for long carrots or a variety called Flyaway if you get problems with carrot fly. Check out the seed catalogues for loads of varieties.

Q. twoistwiceasfun: We are keen growers of fruit and vegetables, but we can't seem to grow parsnips and peas. It feels like we have tried every trick in the book with parsnips, and peas - which are supposed to be heavy croppers - give us barely anything! We don't grow garlic near the veg patch (although do elsewhere in the garden) as I had heard that can cause problems with peas and beans. Advice?

A. Phil: Don't talk to me about parsnips - mine were rubbish this year. The trick is that they need a really long growing season. Sow in early March and you can be harvesting about now until December. But anything sown that early can be stopped in their tracks by any cold weather in spring. My parsnips roots got in a right old twist this year. I think the best ones are the little ones (!) and go for Gladiator or Lancer. Sow in April and harvest earlier. And never let them dry out as the root tips die and they never really produce good crops. 

Now, your problem peas. I like to grow them on soil that has had loads of compost added to it. Again they don't like gong without water and if stressed mildew often attacks. Plenty of compost, plenty of water and don't feed with anything with nitrogen in it (look at packets of fertiliser and they have a N:P:K ratio on the side somewhere - the N is the nitrogen content and should be the smallest figure) Alderman is a good reliable variety and I still like Kelvedon Wonder (old but reliable).

Q. DoraBelvedon:I want an apple tree or two for my rather small garden - thinking about espaliering them against the fence. What is the nicest small dwarf indestructible-type eater and/or cooker?

A. Phil: If you want apple information you've got to go to one of our gardens over the next few weeks. Taste of Autumn is a celebration of the tastes and sights of autumn and every one of our gardens has experts on hand for all your questions. You know where to find the info by now. But quickly - smaller varieties are grafted onto a dwarf rootstock. Look for or ask for a rootstock called M27. Once you have the rootstock you can have virtually any variety of apple on top - I like something called a family apple tree where the growers have grafted a number (usually three) apples onto one rootstock. It's a nifty and tried and tested technique and perfect for smaller gardens.

Q. MoonFaceMama: Do you have any tips for overwintering chilli plants? I've heard it is possible, and we like red chillies!

A. Phil: Keep the plants frost free but they can get cool. A frost free greenhouse is fine, a heated porch-way is okay. Reduce the watering as you can imagine a combination of soggy soil and cold air isn't that good for anything like chillies. Increase watering when growth starts in spring and off you go again. Saying all that, they are easy to grow fresh from seed every year! The teams at the gardens will help you out during Taste of Autumn and actually any time you go! Oh, and be careful of greenfly keeping going over winter on the plants. Just wipe any colonies off with your fingers.


Difficult growing conditions

Q. hobnob57: Do you have any suggestions for a screening plant such a climber that would grow up the north-facing side of an open-slat vertical wooden fence (so there is south-facing sun coming through the gaps)? We would like a bit more privacy, and preferably some pretty flowers to look at too! I have tried clematis a couple of times on the west-facing fence but they just grown and wilt before flowering. I am a gardening novice in Aberdeenshire. 

A. Phil: I would go for a climbing hydrangea. They are fantastic plants for growing in your conditions and produce glossy green leaves and white heads of flowers in summer. Now be patient - young plants can sulk when first planted as they don't wilt or anything but may only produce a few new shoots. Then, after a year they decide you are okay after all and romp away.

RHS Garden

They are easy to look after - nip out the flower heads when they have died and maybe trim back a couple of wayward branches. Perfect.

Your clematis worries me - grow, wilt and die isn't the usual sequence! Plant your clems deep, keep the roots cool and tops in the sun (cover the soil around the plant with large stones to keep them cool)and water in the first year. I also sometimes slide a plastic drainpipe (or clay one if you can get them) over the lower couple of inches of plant to protect the lower stems from slugs and over enthusiastic hoeing. Go for the climbing hydrangea and you'll be fine

Q. ib: We have just put up a chain-link fence at our son's school in southern Spain (inland). It is partly in sun, partly in the shade of a pine forest. It looks awful. What rampant plants (climbers or shrubs) could we plant to soften it bearing in mind that watering is likely to be slack (or nonexistent!) over the summer break? Morning glories seem to be rampant around here, but the other parents reacted in some horror to the suggestion, as they are regarded as a pernicious weed around here. They suggested honeysuckle. Any other ideas?

A. Phil: Both honeysuckle and jasmine love your climate. I would suggest any fast growing annuals from seed - plus the Scrabble sensation Eccremocarpus scaber is a winner - tubular red flowers on scrambling plants. It's also called Chilean glory vine.

There's a nice looking shrubby climber (more of a leaner!) called Sophora and that would love your conditions. Large yellow blooms on the variety 'Sun King'. It does grow in the UK but can get bashed by harsh winters. You could of course grow shrubs near the chain-link fencing rather than try and clothe it - it might give the area more depth. Create a bed of blooms. If you fancy that then rosemary, lavender, Euryops and Cistus would be great. Lots of blooms, all tough enough to stand a bit of drought and easy to grow. Hope that helps and good luck with the project.

Q. Bucharest: I live in Italy, and we don't have a garden, just a balcony. After we saw the vegetable garden that my mum in the UK has, we'd now like to try cooking things to eat. Any suggestions? Especially for a tomato - ours were a disaster last year - which would be balcony-friendly as we are on the south east coast, so it's either hot or windy, but always humid.

A. Phil: What's going wrong? Maybe you had beefsteak varieties and they can struggle in pots and on balconies. Go for smaller, juicer and in my opinion tastier varieties such as Sungold or one of the Tumbling varieties. They are virtually guaranteed to crop well. Next thing is to maybe thing about the watering - humid and windy is bad news for lots of plants. Regular watering is the key. And make sure the compost you are using has some heart to it (old muck at the bottom of the pot is brilliant). I'd also go for basil and any of the herbs.



Q. belledechocolatefluffybunny: My titchy garden is overrun with brambles on an epic scale. How do I get rid of them? Chemicals really don't do anything.

A. Phil: Brambles are not great fun, no matter what size garden you have. Chemicals do work if you are persistent, but if children and animals are around it is always a tricky choice, especially if the environment is a concern. So I'm afraid it's dig them out, dig a few more, and then the ones that reappear, and then some more. You might be able to tame at least a part of the garden. And it will get you fit in the process.

Q. Headfairy: Is there anything I can do about the puffball mushrooms growing in the lawn? Everytime one grows I either dig it out (useless I know because they have underground whatsits) and it leaves a big horrible hole in the lawn which I then have to fill in. Is there anything I can do to stop them growing?

A. Phil: Puffballs decide when they don't want to grow - of course there are chemicals you can slop around to kill fungi but that's not really my thing. Keep picking and you will weaken those mycelial whatsits till they give up and move on. If you need to use chemicals (and it must be a last resort on a plot) use glyphosate. It neutralises on contact with the soil so is best of the chemicals. Good luck - it will be hard work but great fun.

Q. lankyalto:I have a tree stump in my front garden that I would like to get rid of. It was once a conifer of some sort. What is the best way to get it out? I was hoping for it to rot down and be easy to dig out but it is so far resisting.

A. Phil: It is a case of spades and pickaxes. You need to get right under the roots, severing the large roots, watching out for cables and pipes and generally acting like my dentist did getting a wisdom tooth out. It will be worth the effort as it's not a good idea to leave stumps in the ground - they will rot (if they don't regrow) and can attract nasty fungal infections that can spread around the garden.

Q. Aquamortis: I've just taken on an allotment. It is dreadfully overgrown with brambles, grasses...you name it. There are four of us to work on it altogether, so we're not short of labour. But realistically, are we likely to get anything going in it before next spring? Is our best bet just to try to clear the dreaded brambles and then cover it with plastic over the winter to try to kill all the nasties? (Will that even work?)

A. Phil: Congratulations on your allotment and you already sound like sensible plot holders. It can be daunting taking on a full size plot (full of weeds) so yes, decide on what is possible - I suggest half this year and get it cleared. It will take loads of digging, sifting and forking over the soil but you will get there. Cover the other half with tough black plastic sheeting (don't use carpets as the chemicals can leach out). Get half looking good, and it will be a place you want to go to as opposed to that dreadful 'oh no, not the plot again' feeling.


Advice for beginners

Q. Champagnesupernova: We are total novice gardeners with a quite immature garden of about 70ft² which is mostly lawn. We have hardly any bed space but were bought an "instant" container garden" this year - which worked really well although we had far too many salad greens, and our strawberries didn't really fruit. We really enjoyed doing it though. What's best plan for thinking about next year though - can we reuse the containers - or do we plant from seed?

A. Phil: All containers can be reused as long as you wash them out before using again. Refresh with multipurpose compost and away you go. As for planning you cannot beat a roaring fire and this years seed catalogues - it's what autumn's for! Although I am worried that you say your strawberries didn't fruit - did the birds beat you to the fruits? Try the Marshmallow variety for fruits in about 90 days (it worked for me) but do eat the fruits small as they are tastier.

Q. Champagnesupernova:  Could you recommend a simple, very basic book that goes by month? 

A. Phil: I should of course recommend RHS manuals (and there are plenty but look up RHS Simple Steps series) but in addition a series by Alan Titchmarsh called 'How to Garden' are terrific and the ever popular Dr Hessayon range of expert books are still among the best around.


Flowers, trees and hedges 

Q. ampere: I've missed this autumn's window for planting an ornamental silver birch, haven't I? It's -2.5 out there today! When can I have another go? Late spring?

A. Phil: We are only just beginning the start of the best time to plant trees and shrubs - okay, maybe a bit cold this morning, but as long as you don't need a pickaxe to open up the soil or it is waterlogged, there is no better time. The soil is still warm, moist and the dormant trees and shrubs will not even know they've been planted. So get an extra jumper on and get out there!

Q. AnnMumsnet: When should I prune my roses, and how much? I have two in my front garden, 'proper' roses and they have done very well this year, but they are getting tall, about 1.5m at the moment, but I'd rather they were shorter with same amount of flowers. Any tips?

A. Phil: Rose pruning is one of those questions that actually lots of gardeners have different answers to - so don't worry about not really knowing what to do. So, for the record here's my 'in a nutshell' way.

Shrub roses: prune in mid spring; cut out all dead and diseased stems and anything that is crossing over another branch. Cut the main stems back by a quarter. Job done. 
Bush roses (or as you say 'proper' roses!): do the dead, diseased etc pruning as above in mid spring then cut main stems back by a half. Job done! 

Always use clean, sharp secateurs and always do that pruning 'just above a bud and slope the cuts away from the bud to prevent rotting' tips you always read about - it works. And if you like roses look out for a superb new rose garden at Wisley, currently under construction and due to open next year.

Q. 4plus1: I just planted an escallonia hedge a few days ago - should I do any pruning to it now or wait until the spring?

A. Phil: Escallonia is a lovely plant for a hedge. I always prefer to leave a newly planted hedge alone for a few months, or even a year, to get its roots down and established. Also, if you start pruning now a hard frost may damage the cut ends of the branches (and we had quite a severe frost last Saturday so they are knocking around). So leave the secateurs in the shed for now. And great choice of hedge.

Q. flyingintheclouds: I would love to grow so blue bold flowers in our acidic soil, for next summer. Any ideas?

A. Phil: Blue is a gorgeous colour in the garden and forget-me-nots are such an easy plant to grow (but hard to get rid of as they seed all over the place). Hydrangeas like an acidic soil but I cannot resist suggesting mecanopsis. Wow, these are blue flowers plus! Unbeatable, tricky but well worth it. RHS Garden Harlow Carr is trialling some varieties to see which grow best in the north and best to see them next May time. A simple packet of cornflower should grow well and provide you with simple blue blooms. Go for mecanopsis - you won't be disappointed.Phil McCann

Q. DoraBelvedon: How and when should I prune a Magnolia Grandiflora? I have one not up the east wing of my stately home but growing as a tree. It produces the most heavenly flowers but it is getting quite big.

A. Phil: A tree like Magnolia grandiflora - how marvellous. The thing with magnolias is that they don't like hard pruning. The best thing to do is prune back any branches that are crossing other branches, growing vertical and look a bit whippy or anything that is diseased - but do it late spring and midsummer. It gives the cut ends time to heal before winter. So don't hack it back to the ground but nip out the odd branch here and there to keep a good shape.

Q. Amplebosom: We have got a massive cordyline in our very small garden which has just grown and grown. It is now about 7ft tall and very palm-tree-like. I'm not very green fingered and to be honest had no idea it would grow this large! Can you give me any advice regarding how to dig it out in one piece without damaging it? Could somebody re-plant it in their garden? It would be such a shame to kill it.

A. Phil: Cordylines do get big and to be honest, 7ft is a tiddler! They can be moved and now is the time to get your spade out and get digging. The soil is still warm, there's plenty of moisture about and if you do it carefully the plant won't even know it's been moved. Dig deep and quite a distance from the trunk. I'd suggest three feet away from the trunk and dig all around the tree. Dig for I'd say about two feet. Then start digging under the tree. Once all the way underneath the rootball carefully lift the plant and rootball onto a plastic sheet. Wrap it up and transport to its new home and replant at the same depth straightaway. Water it in (even at this time of year) It should be fine next spring. It'll take some effort but seeing it regrow next year will be just rewards.



Q. irmaghostslayer: I have a triangular lawn in my front garden and two sorry-looking flowering bushes. How can I make a pretty front garden? The left side of the lawn is dying as there is a hedge on the boundary. I was thinking of making this into a bed and planting heather, but I'm not sure how this would work all year around.

A. Phil: There's loads you can do to make your front lawn pretty. Heather is one - and they will look good most of the year and can also be smothered in flower. RHS Garden Harlow Carr in Harrogate has some fantastic heather displays just near the new learning centre. You could go for a cheaper option and skim off the turf (or part of it) and sow some wildflower seed (or mixes of seed suitable for say butterflies or bees). For a couple of quid you will have an easy-to-maintain display. If you go down your suggested heather route then do plant a few bulbs at the same time, it will ensure a good spring display. They are all for sale at garden centres and it's the perfect time for planting.

Q. headfairy: I have inherited a really terrible lawn in our new house, nothing I do seems to make any difference. The grass is really sparse to the point that at one end it's just mud. I tried re-seeding in the spring and the grass did regrow, but it died as soon as we trod on it. We have quite a lot of mature trees edging our garden so I've been spiking the lawn and adding sand to aid the drainage and going over it with a lawn rake but that hasn't helped.

I think drainage must be at the core of the problem as we have lots of what I think are puffball mushrooms growing on the lawn too. I'm going to have all our trees pruned as much as possible, but is there anything else I can do to improve the condition of the grass and fill in all the gaps.

A. Phil: I do love a good lawn and if you ever need to get inspiration (or make yourself a little bit envious) go to Hyde Hall in Essex - the lawns there are the best I've ever seen.

The trick is do something now - keep that rake going, keep spiking, feed with a low nitrogen autumn lawn feed to build up roots and keep mowing if the grass keeps growing. Getting more light and air to the surface will help out and no doubt pruning any overhanging trees can only help the situation. Keep doing what you are doing and don't neglect the autumn lawn care.

Q. megonthemoon: We have some lavender in our front garden edging the lawn but it is now very old and woody so needs replacing. Can you suggest some suitable border plants? It's a south facing garden and we'd quite like to have an edible border if possible - was thinking a mix of lavender (any particular species we need if we want to use it in cooking?) and rosemary. Any other suggestions?

A. Phil: Lavender does get old and woody and eventually will need replacing. You can keep younger plants going by cutting back immediately after flowering, but one gardener I know replaces his lavender every four years which is bit costly for me! So, dig out the plants including the roots. Then remove some soil and replace with well rotted compost or soil from somewhere else in the garden. The fascinating thing about lavender is that its roots exude chemicals that actually stop other plants from growing - or at least reduce the vigour of other plants. It's a survival technique to reduce competition - and just to show off for a minute is something called allelopathy. Then plant what you want.

South facing sounds great and English lavender is the usual choice for the kitchen. Any rosemary is good and I wouldn't be without thymes in that area - there are so many different 'flavours' to choose from. In fact, any of the herbs will do well and generally anything with silver leaves will do well - these are adapted to dry and sunny positions.

Last updated: 9 months ago