Knowing when to plant spring bulbs in the UK is the difference between a colourful garden and a bed filled with disappointment. The great news is that there is plenty of flexibility when deciding when to plant spring bulbs in the UK, but there are certainly ideal windows of time for different bulbs.
September: Get Ahead with Daffodils
If you want your daffodils to be established before winter fully sets in, September is the best time to plant them. The soil is still warm from summer which will help them develop roots early. You can even plant them as early as the end of August, but most gardeners find September to be the most ideal time.
Daffodils are not picky on the timing either, so if you are a bit delayed by a week or two, they will still be ok. Plant the daffodil bulbs about 15cm deep, which is roughly 3 times their height. For those of you planting hundreds of bulbs, a bulb planter will help save your back.
You can also plant alliums. These plants are tall with an architectural style and have spherical flowers that are either purple or white. They look brilliant above late spring perennials and for these, be sure to have well-drained soil, as they absolutely hate sitting in water over the winter.
October: The Main Event
This is the climax of the season to plant bulbs. By now you can plant: tulips, crocuses, hyacinths, grape hyacinths, and daffodils if you didn’t get to them in September.
Tulips actually do better if they are planted in October and even early November rather than the earlier months even. They’re a lot more likely to acquire tulip fire disease if they’re planted at a time where the temperatures are still high. Some more experienced gardeners wait until November for tulips specifically, treating them as if they are a different job than the rest of the bulbs.
This is the best time to plant crocuses; they’re the first ones to flower in spring so you can get a glimpse of them pushing through the snow or other foliage. You should plant them in small clusters or “drifts” where you can easily see them such as at the front of a garden border, or a small section of a lawn; about 8 cm is the right depth, so if you can just cover them at that depth you should be good.
By planting these bulbs now, you’ll get the lovely hyacinths blooming and surrounding you with their scent in March and April. they aren’t as flowy as the daffodils, and in fact they are more structured, which is great when you want to put them in a pot at a door or in a more organized plot of flowers. Of course, this is different for indoor planted bulbs, which are better to get started in September if you want them to bloom for Christmas.
November: Last Chance
November is the last month for planting hardy spring-flowering bulbs like tulip bulbs and daffodil bulbs. The soil is colder and wetter but bulbs are tougher than you’d think. If your borders are waterlogged, though, wait for things to dry out a bit. With soggy soil, bulbs can rot before they even start growing.
November is perfect for tulip planting. Professional growers oftentimes intentionally plant tulips late to mitigate disease pressures. As long as the ground is not frozen, you are good to go.
If you are purchasing reduced bulbs from garden centres, make sure to check them out properly. Soft bulbs or those that have signs of mold are to be avoided. If they feel healthy and are firm, the lower price is worth it because they will still do well.
December: It’s Not Too Late
Many people do not realise you can still plant bulbs up until December and this extends to December planting. Naturally, if the ground is frozen or waterlogged you will have to wait til it thaws. However, December planting is just fine in milder parts of the UK like the Southwest or coastal areas.
Since the flowers are being planted a bit later than they should be ideally planted, you might get slightly shorter stems than you would usually, but you still get a decent show, especially with Daffodils, which are very forgiving about late planting.
If you have bulbs that you intended to plant but forgot about, you shouldn’t write them off due to late planting. Just put them in the ground when you get the chance, as the bulbs know what to do.
And Then What?
Flowering bulbs are really late to plant, especially in January or February. You’ll likely get lower quality results due to very little time to establish roots Before you get really good flower quality. The roots need to be put in as much energy as possible to constant flowering.
If you are really late to plant, you are really limited to planting very little in terms of flowering. You may need to buy bulbs that are already ‘in the green’, which means they are already a growing plant that has its leaves established, usually in February or March. You may be able to get Snowdrops, as they are a common bulb sold in this style, which is much easier to establish than the regular dry bulb. This may also get more expensive, but works better in the long run.
If you have leftover bulbs, you may also have the option to pot them and keep them in a cooler place. You can leave them in the pot to flower, or you can plant the bulb later after the flowering. You may be able to get them to naturalize over time.
Planting Spring Bulbs
Honestly, anytime is a good time to plant spring bulbs, because, yes, there is a better time, but a bulb that’s been sitting in a packet for a while is going to do a lot worse than a bulb that’s been planted late in the time window. Most bulbs won’t get bad the long the time window goes on, and even if you do miss it, the flowers will most likely still be able to bring some nessecary joy to a spring garden, even if it takes some extra time. They’ll probably just be a few more flowers than you would have gotten at the right time and those flowers are definitely going to be a lot better than no flowers at all.