What to do with tulips and daffodils in pots after flowering
Peter Dowdall, Irish horticulturist and broadcaster, explains what to do with bulbs in pots once flowering is over, why tulips should be lifted and daffodils need not be, and how to store and replant them properly.
The question comes in every spring without fail, usually from someone looking at a collection of pots that were spectacular a few weeks ago and are now looking tired and messy, the flowers gone and the foliage starting to yellow. What do you do with them? The honest answer is that it depends entirely on what is in them, because daffodils and tulips are not the same plant and they do not behave the same way after flowering. Treating them identically is where people go wrong.
Leave the foliage alone
The starting point, regardless of what bulbs you have, is to resist the urge to cut back the foliage the moment the flowers are finished. That yellowing, untidy-looking growth is doing important work. The leaves are still photosynthesising and pushing energy back down into the bulb, building up the reserves that will power next year's flowers. If you remove that foliage before it has died back naturally, you are interrupting that process and the bulb will be weaker for it. Let it go. Wait until the leaves have gone completely yellow and limp, which in Irish conditions typically means six to eight weeks after the flowers finish. Deadhead the spent blooms if you want to keep things looking slightly tidier, but leave the leaves alone.
Lifting, drying and storing
Once the foliage has died back fully, the correct approach for all bulbs grown in pots is to lift them, clean off the old compost, let them dry out for a few days somewhere with good air circulation, and then store them somewhere cool, dry and dark until planting time comes around again in autumn. Wrap them loosely in newspaper or lay them in a tray, label what they are, and leave them undisturbed until October. A shed, a garage shelf or a cool spare room all work. What you want to avoid is anywhere that gets damp or where temperatures swing dramatically. The bulb at this point is dormant and simply needs to stay dry and cool until it is time to go back into the ground.
Daffodils: lifting is optional
They will sit happily in the pot or the ground from one year to the next. Watch for overcrowding, and lift, divide and replant every three or four years when flowering starts to thin.
Tulips: lift them
A tulip bulb left in warm wet Irish soil through the summer is sitting in the exact conditions tulip fire needs. Lifting and storing dry is the only reliable way to keep them going.
The problem with leaving tulips in the ground is not the winter. It is the summer. A tulip bulb sitting in warm, wet Irish soil through July and August is in exactly the conditions that tulip fire needs to take hold.
Daffodils: you have a choice
With daffodils, and with many other spring bulbs such as alliums, muscari and snowdrops, you have the option of leaving them in the ground or in their pot rather than lifting every year, and in many cases they will perform perfectly well. The foliage still needs to die back naturally, but once it has done so, a pot of daffodils can be moved to a quiet corner and left to its own devices until the following spring.
What you need to watch for over time is overcrowding. Daffodil bulbs multiply, producing offsets, and after three or four years in the same pot or the same spot in the ground, a clump that was flowering magnificently can start to produce a lot of leaf and very few flowers. The bulbs are competing with each other and none of them has quite enough space or nutrient to perform properly. If you notice your daffodils giving you less flower year on year, this is almost certainly the reason. Lifting, dividing and replanting every three to four years solves it. It is not complicated, but it does need doing.
Tulips: lift them
Tulips are a different matter entirely, and this is where I would be direct with people. If you want reliable tulips year after year, lift them. The problem is not the winter in the ground, it is the summer and early autumn. Once the foliage dies back and the bulb goes dormant, it is sitting in warm, wet Irish soil through July, August and September, and those are exactly the conditions that favour tulip fire.
Tulip fire is a fungal disease caused by Botrytis tulipae, and it is particularly damaging in our climate because it thrives in damp, mild conditions. The fungus produces small resting structures called sclerotia that persist in the soil for several years, so once it becomes established around a tulip bulb left in the ground, it is very difficult to get rid of. It is also significantly more active at higher soil temperatures, which is why lifting the bulb and storing it somewhere cool and dry through the summer removes it from the environment where the disease does most of its damage.
Many people try leaving tulips in the ground and find that the first year back they get a reasonable display, the second year noticeably thinner, and by the third year a handful of weak, short-stemmed flowers from a pot that once looked extraordinary. That decline is tulip fire doing its work in the soil. Lifting and storing is not extra effort for the sake of it. It is the only reliable way to keep tulips performing year after year in Irish conditions.
Replanting in autumn
When you come to replant in autumn, wait until the soil temperature has dropped, which in Ireland usually means October at the earliest for daffodils and November for tulips. Bulbs planted too early into warm soil tend to put on growth before winter arrives and can be damaged by the frosts that follow, and in the case of tulips the warm damp conditions of an Irish September favour the fungus all over again. Planting into cooler soil inhibits it and gives the bulb a cleaner start.
Getting the compost right before you plant matters as much as the timing. Planting bulbs into dead, compacted or waterlogged compost is the quickest way to lose them over winter, regardless of how carefully you stored them through the summer. Start with a well-structured, free-draining mix that holds moisture without holding water.
Bulbs are only one part of the planting year, and the autumn window that suits them is the same window that suits most of what goes into an Irish garden. If you are planting more widely, when is the best time to plant in Ireland sets out the planting windows for trees, shrubs, hedging and perennials alongside the bulb schedule.
Bulbs need free-draining, living soil to perform year after year. NutriChar is my biochar plant food, made using a patented process, and worked through the compost before planting it improves structure and drainage so the soil holds moisture without holding water. Soil first, then better roots and longer results.
Ask Peter
Not sure what you are dealing with in your pots?
The general guidance above covers the most common situations, but bulbs in pots throw up specific questions depending on what you planted, how they performed this year and what your conditions are like. If you are unsure whether to lift or leave, or if something does not look right with your bulbs after flowering, Ask Peter directly and describe what you are seeing.
If you are planning a wider scheme rather than a few pots
Bulbs work hardest when they are planned as part of a sequence: what flowers before them, what follows them once the foliage is dying back, and how the border or the group of pots reads across the whole season rather than for a few weeks in April. That is what a planting plan sets out, worked around your soil, your aspect and Irish conditions.