The April sweet peas trick: pinch out tips for more flowers

Plenty of hobby gardeners miss the April window for masses of scented sweet peas - one small move decides whether your summer vases are full or empty.

If you want to carry armfuls of fragrant cut flowers from your own garden in summer, April is when you need to act. With sweet peas - the classic climbing summer favourite - this is the month when the key mistake is made: the plants grow, but they aren’t trained properly, and the consequences only become obvious weeks later.

Why April is the month that makes or breaks your sweet peas

Sweet peas begin delicately, then suddenly shoot up fast. At this stage they need guidance, not sympathy. If you simply let them “get on with it”, you’ll end up with long, thin stems and fewer flowers - often much later than they could have been.

In April you decide whether your sweet peas will stand bushy and packed with flowers, or whether they’ll only scramble sparsely in summer.

Broadly speaking, April comes down to three things:

• pinching back young shoots correctly
• gradually getting plants used to wind, sunshine and temperature changes
• planting out in time with sturdy supports in place

Take these three steps seriously and you’ve got a strong chance of near-continuous flowering right into late summer.

The state of your plants: where are you starting from?

Before you begin, it helps to be honest about your starting point. In practice, there are usually three scenarios:

• You raised plants in pots in autumn or winter.
• You bought young plants from a garden centre.
• You haven’t sown yet and you’re wondering whether an April sowing is still worth it.

What matters most is the length of the shoots. As soon as your young plants are roughly 12–20 centimetres tall, the moment for the decisive step has arrived. Treat that range as your starting signal.

The step people forget: pinch out the tips instead of letting them keep climbing

This is where many go wrong: the plants look healthy and they’re growing well, so you let them continue racing upwards. From the sweet pea’s point of view that makes sense - from a gardener’s point of view it’s a problem.

What actually happens when you pinch out

When shoots reach 12–20 centimetres and have two to three pairs of true leaves, pinch out the growing tip. You can do it with thumb and forefinger or with clean scissors.

Removing the shoot tip forces the sweet pea to branch - instead of a meagre stem you get several flowering shoots.

The results:

• more stems per plant
• noticeably more buds and flowers
• a sturdier structure, fewer floppy, elongated “fishing rods”

Important: remove only the tip - don’t make a half-hearted cut somewhere mid-stem. One clean snip just above a leaf node is enough.

Pinched too late - or not at all? Here’s what tends to follow

If you skip pinching out, later on you’ll often be dealing with:

• sparse flowers on long, thin stems
• a much later flowering period
• plants that topple more easily or get whipped about by the wind

Once a plant develops a weak framework, it’s hard to correct. That’s why getting the timing right in April matters more than any expensive fertiliser.

Hardening off young sweet peas: outside air - but not a cold shock

Plants raised in a warm room or greenhouse can be shocked outdoors: wind, sun and temperature swings act like a mini stress test for unprepared seedlings.

How to get them used to being outside without “drama”

The standard method is called hardening off and takes one to two weeks:

• At first, put them outside for only one to two hours in a sheltered, bright spot.
• Increase the time outdoors a little each day.
• Bring them back inside or into a frost-free greenhouse on chilly nights.
• Avoid harsh midday sun for the first few days; morning or evening light is better.

A simple cold frame, an unheated greenhouse, or even a covered balcony works perfectly as a transition zone. After around 7–14 days, healthy plants are ready for their final position.

Planting out: spacing, depth and the right moment

Once nights are reasonably mild and the soil has started to warm, sweet peas can go into the ground or into large pots. As a guide, aim for a soil temperature of about 15–16 °C.

Plant properly - so sweet peas settle in well

• Planting depth: about the same depth as in the previous pot.
• Spacing: roughly 15–20 centimetres between plants.
• Soil: loose and humus-rich, improved with well-rotted compost.
• Containers: choose deep pots where possible, at least 25–30 centimetres.

Root space plays a big part in how many flowers you get - cramped, shallow pots noticeably hold sweet peas back.

Put supports in immediately - not “later on”

Sweet peas are classic climbers: without support, the stems sprawl on the ground, tangle up, and snap more easily. That’s exactly why supports should go in at planting time.

Support options that work well

Good choices include:

• trellis fixed to fences or walls
• obelisks as a focal point in the border
• several bamboo or hazel canes tied together at the top

Tie stems in loosely, ideally with soft twine or dedicated plant ties. Hard wire can cut in quickly and damage the stems.

Summer care: watering, feeding and routine checks

To make sure the plants really deliver on the April potential, they need consistent attention as the season progresses.

Task	Frequency	Note
Watering	regularly, keep soil slightly moist	never waterlog; soggy conditions encourage fungal disease
Feeding in pots	every 2–3 weeks	liquid flowering-plant feed at a weak concentration
Tying in	as needed	gently guide new shoots onto the supports
Health check	weekly	watch for aphids and powdery mildew

Aphids, powdery mildew and poor flowering: common issues and quick fixes

In warm spells, pests and fungal problems often appear. If you act early, you can prevent bigger damage.

• Aphids: hose off with a strong jet of water or spray with a mild soap solution.
• Powdery mildew: remove affected leaves, avoid watering over foliage, and tie plants in more openly for airflow.
• Few flowers: check whether you really pinched out in April and whether plants are getting enough light and nutrients.

When flower numbers are low, the cause is often not a “bad summer” but a missed cut in spring.

Cutting correctly for fragrant summer posies

If you want the plants to keep going, how you cut for the vase matters too. Ideally, cut in the morning when stems are well hydrated.

• Cut only strong, long stems.
• Always leave a few buds on the plant so it keeps producing.
• Don’t cut too low: leave three to four nodes above the ground.

Harvesting regularly encourages fresh bud formation. If too many seed pods are left on the plant, sweet peas quickly switch into “ripening” mode and flower less.

Why the April trick works for other climbers too

The idea behind the April pinch - redirecting growth rather than letting everything go straight up - applies to many climbers. Even with other annual climbers such as ornamental bindweed or black-eyed Susan vine, it’s worth taking a critical look early on at stems that are getting long and unbranched.

If you generally tend to be gentle with young plants and “don’t touch them”, you often deny yourself the best display. Sweet peas, in particular, cope surprisingly well with a decisive pinch and repay it for months with fragrant armfuls of blooms - provided you don’t forget that crucial little April step again.