Salvias - Expert Tips on How to Grow These Long-Lasting Garden Flowers

Salvias are one of the most brilliantly colorful and ornamental plants you can have in your garden and they flower for months on end. So I've come to talk to the UK's leading salvia expert William Dyson of Dyson Salvia Nurseries which are in the garden at Great Comp. Great Comp gardens are considered to be one of the finest gardens to visit in Kent and as well as having a romantic ruin and woodland walks and an Italian garden they've also got lots and lots of It's Alexandra here from the Middlesized Garden YouTube channel and blog and I'll put links to Great Comp and Dyson Salvias and any other resources we mention in the description below. And if you're new here, the Middlesized Garden uploads weekly with tips, ideas and inspiration for your garden, so if you'd like to see the videos when you open up YouTube, tap subscribe. So William, tell me what's the really best thing about salvias, the reason why we should put them in our garden? Because they flower for such a long long period, they don't take an awful lot of looking after and the range of colors is fantastic, everything from white through all the shades of pink, purples, blues right up to almost nearly almost black. And in terms of who can have them in their garden, what sort of gardens they're best for, what would you recommend? Well I think that it depends on what type of salvia you want to grow. If you're looking at the shrubby Mexicans, of which we have rather a lot here, you need to have a good sunny position and well-drained soil and that's basically all there is to it. If you've got more shade, maybe not quite so well-drained, then some of the taller, large-leaved salvia such as the Salvia Concolor Garinutica involucrata. And generally if you look at salvia, the larger the leaf, the less light levels they require really. So if you want one for part shade, go for a slightly larger leafed salvia? Yeah absolutely. I must say that makes a lot of sense because I've got a salvia in too shadier position at the moment and it's got very small leaves and it's not looking very happy. They tend to lean to the light and they don't flower as well. How do we choose salvias? What plants do they go well with? They go well with all kinds of things. I'm also quite keen on Miscanthus cultivars and I've got a big collection of Miscanthus and they go really well with those, but they go well with them. If you look over there, we've got diacidas with them, we've got penstemons with them and anything really that will have that sort of period of flowering is great. So you have a real explosion of colour if you like or just grow them with other salvias. You could grow a combination of shrubbies and larger-leaved forms. Some of the later flowering, what we call short day salvias, things like salvia leucantha, have got beautiful foliage and if you have in the foreground perhaps you would have some of the shorter salvia microphylla with salvia leucantha behind and then the salvia leucantha doesn't start flowering until September and that will go on right until the first frost etc. But it's the variation in form of the leaf as well, so you've got textural contrast there, but certainly different grasses as well is a good combination. And can you grow salvias with roses? You can and I think Sarah Raven's quite keen on that. She's done a bit of research in putting shrubby Mexican salvias beneath the roses and she says that it does actually reduce the attacks of black spot and what have you and other fungal diseases. I haven't tried that myself, but it seems to me that that would be an ideal combination because particularly if you've chosen the heights correctly where you've got a tallish rose and a medium-sized salvia, the salvias are going to keep on flowering and flowering, so you've always got that season of interest for an area which might not be a particularly, you know, a rosebed might not necessarily be a particularly long-flowered area, so I think that's good. I mean I've actually been trialling growing salvia, shrubby Mexicans, with apple trees because I planted some apple trees in my own garden about three years ago and I thought well let's put a few salvias around the base of these and what that does it actually increases the amount of beneficial insects that are in the, you know, natural predators that are in the area and it also looks fantastic, but you've got bees and hoverflies which will come and return to it and then presumably they've got some sort of a memory or they pass it on into the hive and then in the spring they'll come and visit the apples to pollinate those, so that's quite a nice combination as well. Can salvias grow in pots? Yes very much so, I mean if you think about when we were exhibiting at all the major shows we had to have, you know, a whole range of things in containers and some of these would be in great big containers and some would be in quite small containers, but they are eminently suitable for growing in a pot, just make sure that the compost that you use is well drained. And also presumably as well if you're very wet heavy clay soil which salvias won't like either that or creating a raised bed. The only thing with it with growing in containers is they'll run out of food and when you find the lower leaves of the salvia starting to turn yellow that means they're running out of nitrogen because nitrogen is a mobile element and what they do is they take the nitrogen from the lower leaves to keep feeding the tips. Once that starts happening just get some tomato food and give them a water with that every couple of weeks and that keeps If my salvia is not flowering, why is it not flowering? It could be that you've got it in too much shade or because you've given it too much food. I mean if you overfeed salvias you'll get an exuberant amount of growth and very little flower. And generally if I'm just planting salvias in my borders and I have mulched my borders once a year so they're in really reasonably good state, would you recommend fertilizing salvias? Not at all, not at all, no, not at all, no, they'll get everything that they need out of the ground. So that's helpful, so you don't have to fertilize them and what about pests and diseases? The main ones early in the year you'll get something called capsid bug which can fly in and if you find that the tip growth where the flowers are forming on your shrubby Mexicans, well on all of the salvias, is starting to have little shot holes all over it that's an indication that the capsid bugs have been in and fed and they feed on the absolute tip the apical meristem and you don't know they're there because they fly in and they move really quickly then they fly off again and a fortnight later you find all this evidence where they've been. That can cause distortion of the flowers and abortion of the flowers so they're not good. Aphids and whitefly, they're more common if you're growing them under cover but you will pick it, you will get bits of that. We don't tend to treat aphids and whitefly in the garden because there are plenty of other beneficial insects that will deal with them, but if I'm looking at an area of salvias that I'm looking for propagation material from, so in early May when they're coming into growth, if I know there's a variety that I need to collect stock from, I'll go over and I'll give them a quick squirt with something to kill any capsid bugs that are around. So when should you be planting salvias? You can plant them anytime in England, anytime from late May onwards to probably, I wouldn't go beyond about late August really, early September. The longer they're in the ground, the longer they've got a chance to build up a good root system. If you're going somewhere and you've got an opportunity to buy a salvia that you're never likely to see again and it's in October, just put it in a cold greenhouse or a cool greenhouse for the winter, put it out in May. So what about pruning? Well pruning is very important and pruning is more important with the shrubby Mexicans. The herbaceous types we don't worry about because all we do with those is we cut them down either at the beginning of the winter or as we do at the end of the winter in March and then all the new growth comes from underground and we don't touch them then. But the shrubby Mexicans, in here we do them late March which equates to really early to mid-spring and we can prune down fairly hard but we're getting rid of all the dead growth on them but we are making sure that we have always got some green emerging shoots below where we're cutting. If we cut into directly into brown dead wood it's very likely that we will just take the plant out altogether. The other thing, the important thing is you then after that pruning you get a rush of growth and typically they will start flowering in May. I mean they will go on and on full stop you know but but you you find that when you get to mid-July end of July there are tip bearings so there's a few flowers at the top that all the flowers below are spent and at that point you should go and take cut them again prune them again and take about a third off so don't just deadhead them take about a third of the height of the plant and that will encourage all the shoots below to burst into growth and they will all flower and it's probably between five to six weeks before they re-bloom and then then that will be a full re-blooming which will keep growing right the way through until the early winter and the the advantage with doing that is that you're actually keeping the shape of the plant so you're improving the shape because every time you prune them they are branching out and you're getting a better a better denser shrub really. So it's a pretty straightforward plant to look after you basically you plant it you prune it yeah do you need to water them at all? Very very rarely the larger leaved types yes if you've got a drought things like salvia atrocyania salvia con color they are going to look thirsty if they're particularly if they're growing in full sun they're a little not so bad if they're in partial shade but the shrubby Mexicans they don't need it they are incredibly drought tolerant. In terms of winter they come from Mexico they're to the southern United States and Mexico and Bolivia and things like that so how do they deal firstly with our English winters and also with some of the harsher winters that people have in say zone five in the United States? Okay well the shrubby Mexicans they tend to in a mildish winter they will retain some of their leaves and in a really hard winter they may be clobbered altogether some of the shrubbies which have salvia microphylla in their parentage have got the ability to regrow from below ground so they send up rhizomatous growth the taller types the garonitica types all of that growth is generally in a general winter particularly well where we are for instance where we don't go below about minus 11 centigrade they will be the tops will be cut back and as long as you're on well-drained soil they will re-emerge but if you're in an area where you've got temperatures that go down sort of minus 20 and you're wet as well then that kind of limits your opportunities and you're probably better off digging them up giving them a ride in a wheelbarrow and potting them on and growing them over winter in a more sheltered accommodation and then putting them back out again in the spring. And if you're leaving them out in the sort of milder up to about minus 10 celsius then would you pile lots of manure on? I tend not to use manure with salvias because that tends to encourage too much weak growth a lot of sappy growth but I would use something like wood chip and then clear it away in the spring and we find that the particularly the the tubers for tubers forming species such as the salvia patterns for instance if you've got very very hard winters where the frost will penetrate low a good pile of the wood chippings around them would be would be ideal and then clear the clear that away early in the year. But the shrubbies we wouldn't recommend any form of mulching for those because that will cause the stems the branches to rot. Are they good for wildlife? Very very good for wildlife they are the bee's number one source of nectar and they've got quite a long flower to you which doesn't actually suit the the length of the proboscis on an English bee, either a honeybee or a bumblebee, but what the bees have done they've they've adapted to this they come along and they take a shortcut into the nectary by drilling a hole in the side of the flowers this used to annoy me intensely when I was having collections that I was taking up to Hampton Cork Flower Show having all these holes drilled in the flowers but but in the garden one doesn't notice it quite so much but you have to remember that in their natural environment they would be pollinated by things like hummingbirds and carpenter bees and they have much longer proboscis so they can go and collect their nectar from the in the usual way but yeah so fantastic for hover flies bees we have hummingbird hawk moths that come and will feed on it so they're great in that respect. Can salvias be moved if you've got a salvia that's been somewhere for quite a long time indeed as I have because I've obviously planted one in the wrong place it's been there for 10 years can I move it? You know I can honestly say I've never tried it I haven't because if something's in the wrong place and I've usually got a lot more so I'll just dig it up and chuck it in the compost heap but you can move plants that have been in for the season you know tender stuff that you want to move indoors you can dig that up with a good root ball but reduce the root to shoot ratio is the important thing to remember so if you're removing a bit of quite a bit of the root when you dig up you need to remove a correspondingly large amount of top so root to shoot ratio but I mean shrubby Mexicans people talk about that I say well the best thing to do if you've discovered it's too big for there is just take some cuttings from it grow those on and put those somewhere else and then you can try digging it up and if it dies and you've got some some backup there. If you're interested in other brilliantly colorful plants that add wow factor to your borders I've got a wow factor plants playlist at the end of this video and let me know what you think and thank you for watching goodbye