Gadenin日本語Get the appPicking is the job, not a bonus
A sweet pea exists to make seed. Every flower it opens is an attempt at a pod, and as soon as pods begin to fill, the plant reads its work as done and stops producing new flower stems. This happens fast. A row left unpicked for a week and a half in midsummer will be covered in fat green pods and will never flower well again that season, no matter what you do afterwards.
So pick everything, every two or three days, whether or not you want the flowers indoors. Take the whole stem down to its joint with the main stem, not just the flower head. Take stems that are fully open and past their best as well as fresh ones. And take off any pod you find, however small, because one pod left to swell on a plant is enough to slow the whole thing down.
This is the difference between a sweet pea that flowers for six weeks and one that flowers for twelve. It is not fussy or optional maintenance; it is the central fact of growing the plant. If you are going away for two weeks in midsummer, strip every flower and bud from the row before you leave rather than coming back to a plant full of pods.
The flowers cut well and last four or five days in water, so the picking gives you something. Cut in the cool of the morning, put the stems straight into water, and strip any leaves that would sit below the waterline. The scent is strongest on a warm still morning and fades in a hot dry room.
- Walk the row every two or three days Take a container of water with you and cut every stem that is open, including ones already fading. Cut down at the joint with the main stem so no stub is left to die back. Two or three minutes per pass is enough on a domestic row.
- Remove every pod you find Pods look like small flat green pea pods behind a faded flower. Pinch them off at any size. Missing a few does no harm; leaving them deliberately, or letting a week go by unpicked, is what ends the flowering.
- Strip the row before you go away Take off all flowers, all buds and all pods before a holiday. A stripped plant restarts within a week or two; a plant that filled its pods while you were away does not restart at all.
- Cut in the morning, into water Stems cut in the cool of the morning last longest and carry the most scent. Take a jug of water out with you rather than laying stems on a hot path; wilted sweet pea stems rarely take up water properly again.
Water deeply and never let them dry out
Sweet peas are thirsty. They carry a lot of soft growth on hollow stems and they lose water fast on a bright day, and they were bred from a plant that grows in cool damp conditions. Dry soil at the roots shows up first as buds that yellow and drop before they open, then as short stems with only two or three flowers, and finally as an early finish to the whole season.
In the ground, soak the row thoroughly once or twice a week rather than sprinkling it daily. A gallon (4 to 5 liters) per plant at each watering is not excessive in hot weather. Water at the base, in the morning, and keep it off the foliage: wet leaves in crowded growth are how mildew starts.
Mulch the base with two inches (5 cm) of compost or well rotted manure once the soil has warmed in spring. This is the single most effective thing you can do for a sweet pea row, because it holds the moisture and feeds at the same time. Keep the mulch an inch clear of the stems themselves so the base does not sit wet.
Containers are harder work and are the main reason people conclude sweet peas are difficult. A pot full of sweet peas in summer needs watering every day and sometimes twice, and the deepest container you can find will still dry faster than open ground. If you grow in pots, use one at least fourteen inches (35 cm) deep, plant fewer per pot than looks right, and check them every morning without exception.
| Symptom | Likely cause | What to do |
|---|---|---|
| Buds yellow and drop before opening | Dry roots, or a cold night in spring | Soak deeply and mulch; cold nights need no action, it passes |
| Stems suddenly short with 2 to 3 flowers | Heat, dryness, or the plant setting pods | Water heavily, strip all pods, and shade in the hottest hours if possible |
| Whole plant pale and slow, yellowing leaves | Hungry soil or a pot that has run out | Half strength high potassium feed weekly; mulch the ground row |
| Enormous leafy growth, few flowers | Too much nitrogen | Stop nitrogen feeds; switch to potassium only |
| Flowering stops in early summer | Pods left to set, or the arrival of real heat | Strip every pod; keep water up; expect a partial recovery only |
| Lower leaves yellow and dry from the base up | Normal ageing plus shading from the growth above | Remove the worst leaves to keep air moving; nothing else needed |
Feed for flowers, not for leaves
Sweet peas are hungry, but the type of feed decides what you get. Nitrogen makes leaf and stem. Potassium makes flowers. A general purpose fertilizer applied through the summer gives an impressive green curtain with disappointing flowering, which is the same trap that catches people with many flowering annuals.
Prepare the ground properly in the first place and you can feed very little afterwards. Dig in plenty of well rotted manure or compost the autumn before planting, ideally into a trench a spade deep, and the row will carry itself into midsummer without help. This preparation is worth more than any liquid feed later.
Once the first flower buds show, start a high potassium liquid feed, the sort sold for tomatoes, at half strength every ten to fourteen days. Keep it going until the plants finish. In containers, feed weekly rather than fortnightly, because every watering washes nutrients out of the bottom of the pot.
Do not feed a plant that has stopped flowering because it set pods. Feeding will not restart it; stripping the pods might. Feeding an already lush, flowerless plant just adds more leaf to the problem.
Heat, and what to record for next year
Heat, not age, ends the sweet pea season in most gardens. The plant grows and flowers best when days are mild and nights are cool, and once daytime temperatures settle into the high eighties Fahrenheit (around 30C) the stems shorten, the colors bleach, the scent fades and flowering tails off within a couple of weeks. Nothing reverses that; you can only delay it with water, mulch, some afternoon shade and relentless picking.
In cooler summers the same plants keep going well into late summer, and a row that has been picked hard the whole time will still be producing usable stems when neighboring annuals are finished. The gap between a well managed row and a neglected one is largest in exactly these late weeks.
Write down three things through the season: the date of the first flower, roughly how many stems you cut on each picking round, and the date flowering fell off. Add one line on what you fed and when. That is enough to answer next spring's questions about whether the autumn sowing paid off and whether your row needs more water than you gave it.
Also note the position of the row and which end finished first. Almost always the end that finished first is the driest or the one that catches the most afternoon sun, and once that is written down the fix is obvious rather than a mystery repeated every year.
One pod left to swell is enough to slow a plant down, and sweet pea pods are poisonous despite looking like edible peas. Pick them off and dispose of them rather than leaving them where a child might treat them as vegetables from the garden.