Biennials, are they worth the effort, he asked.

Verbascum creticum, a biennial with presence in our rock garden

Each Sunday morning at 7.45am, I have a chat with Tony Murrell on Radio Live’s Home and Garden Show. We cover a wide range of gardening matters and during the week before we have a discussion by phone or email to agree an upcoming topic. As an aside, the recent release of very encouraging listener figures for this time slot has sharpened our focus somewhat. There is a scary number of folk out there who listen at that hour.

Today we talked about gardening in the very dry conditions that much of the country is currently experienced, which was my suggestion. Tony’s suggestion of ‘biennial plants – are they worth the effort?’ was put off until next Sunday. But since he suggested it, I have been thinking of biennials which I had never considered as a plant group before.

Ranunculus cortusifolius in biennial for us

Yes! Biennials are worth their place in the garden. I am struggling to imagine our garden without the biennials. Mind you, we don’t put any effort at all into most of them. They are plants that we let seed down, pulling out those which are in the wrong place and letting the other volunteers remain to continue their life cycle.

Annuals are plants that complete their lifecycle in under a year from germination to setting seed and dying. Biennials have a two year life cycle. Most of them will establish themselves in the first year but not bloom until the second. Because of that year spent establishing themselves, many of them can be quite large growers – thugs, even, as Mark calls them. To let these types of biennials seed down, you do need quite a bit of space.

Common they may be, thuggish even, but foxgloves have presence

Some of our key plants are biennial. I am thinking of the large flowered, yellow Verbascum creticum, the biggest geranium of them all, G. madarense, Angelica gigas and … foxgloves. Foxgloves really do fit the thug category but we are fond of them, even the common pinky purple one that is regarded as a weed in this country. We have been working to get the white ones naturalised around the place. “Are you going for the Hidcote look,” Mark asked, for that is the first place where I saw extensive and eyecatching use of pure white foxgloves. I also like the pastel shades, especially pastel apricots, so I have been summarily despatching the deeper pink forms anywhere near the pale ones to stop the bees from cross pollinating the colours, lest they all return to the dominant dark pink over time.

Sadly, most of these meconopsis have died out in this border now

Not all biennials are self-sustaining and strong growing. The highly desirable meconopsis, Himalayan blue poppies, which are extremely difficult in our climate, tend to be biennial – even those that are touted as perennials in more favourable climes. And it has never seeded down for us. To keep it going here, we have to gather seed and raise it in trays to plant out once it is growing. Ranunculus cortusifolius is also biennial in our conditions but it seeds down and keeps going as long as it has its own area where it can be left to do this.

Parsley is biennial, fennel usually so, and what would life be like with parsley in the garden? Once you have it, you just have to make sure that you leave at least one plant a year to seed down in order to keep a permanent supply.

Biennials, like annuals, only represent effort if you are having to raise them from seed or buy them to plant out each year. If you allow them to seed down and find their own niches in the garden, they can be very rewarding, requiring minimal effort. Wanting such plants to seed down is yet another argument for not being too quick to get out the glyphosate and control any germinating plants by spraying them out as soon as they appear, on the assumption that they must be weeds.

Speaking of verbascums, can any UK readers enlighten me on what happened to the blue as blue verbascum named ‘Blue Lagoon’ that debuted at Chelsea in 2012? We have never seen any mention of it since, let alone seen it incorporated into any of the gardens we have visited so wonder if it was a fizzer in the end.

Blue meconopsis take a lot of effort to keep going here. But for this sort of display, the effort is worth it


6 thoughts on “Biennials, are they worth the effort, he asked.

  1. tonytomeo

    Where foxglove naturalizes, it does not matter that it is a biennial. I mean, no one really looks at it to notice what it is doing until it blooms. By then, it does not matter if newer plants below are not blooming. Some people dislike it because it is so persistent. I think that it is only persistent in areas where it happens to look good, but does not seem to get in the way.

    1. Abbie Jury Post author

      Dead easy to pull out, which is to its credit. I think the NZ disdain for it possibly originates with a collective nostalgia for when we all felt that plants that invade the pasture lands of poor, plucky, struggling farmers should be spurned. Now farming has taken on the corporate model and involves Big Money but the quaint attitudes of the past persist.

  2. John Kingdon

    I think Blue Lagoon was developed by Thompson and Morgan around 2010 though I think it was Hilliers who put it on the map when they featured it in their 2012 Chelsea display. It did disappear quickly (as I’ve noticed a few of T&M’s introductions do – a subject for it’s own discussion maybe) and not even T&M list it now. I’ve totally given up on Meconopsis; the only way I could get any sort of display was to buy 2-3 litre plants every year. Indeed, checking back through my notes, I rarely bother with biennials at all now, save for foxgloves.

    1. Abbie Jury Post author

      Thank you for that. We figured that maybe it had not been as reliable as claimed and dropped off the market – a shame. Pure blue verbascu should be an excellent addition.

  3. Tim Dutton

    We’ve managed to establish a preponderence of pure white foxgloves by religiously pulling out any seedling that shows the slightest tinge of pink on the stems over many years as well as those that open the dark pink flowers which we missed. A couple of years ago I also collected seed from one particularly large white one and sowed them. This year we have a sizeable number of pure white foxgloves that are all well over 2 metres tall: pretty impressive. Leaving in some pink seedlings has also given us a nice selection of pale pink plants this year in amongst the ‘standard’ dark pink (and like you they are getting pulled out in the hope we’ll be able to get a line of pale pink) and we’ve also got a couple of white ones with dark spots in the throat. We wouldn’t be without them. Nor would I want to be without Geranium maderense, which grows well for us and is left to do its own thing, though we do have to weed it from paths quite often.

    1. Abbie Jury Post author

      What I really like about the process you describe, Tim, is how closely it encourages you to look at the individual plants and their blooms.

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