Diarmuid Gavin’s guide to the best summer bulbs

From hardy lilies to exotic Tigridia pavonia, here are the top varieties for a colourful display

In general, summer bulbs do best in a warm sunny spot

In general, summer bulbs do best in a warm sunny spot

Snowdrops

Chaenomeles x superba ‘Pink Lady’

In general, summer bulbs do best in a warm sunny spot

Diarmuid Gavin

March 12 2022 07:00 AM

Spring is the air and the ground is warming up. It’s time to get planting and pack our plots with summer colour.

There’s no excuse — you can pick up a good selection of summer bulbs along with your grocery shopping. The contents of the packets don’t always look very promising — just a collection of dry bulbs — but the packaging usually displays glossy photographs of temptingly beautiful blossoms. So how do you transform the inside into what is promised on the outside?

To get going, they need light, water and a growing medium — compost or soil. Some are tender, such as begonias and gladioli, so these need to be started off indoors and then gradually brought outdoors to their final planting position when the frost has gone. This varies considerably from midland to coastal areas, so tune into the nightly forecast for overnight frost warnings.

Others such as lilies and ranunculus are hardy and can be planted either in autumn or spring.

Adding well–rotted manure or compost to the planting hole will help with fertility and drainage, but if your soil is very heavy clay, you could pop some horticultural grit at the bottom of the hole as well — most bulbs don’t like soggy bottoms. In general, summer bulbs do best in a warm sunny spot. Here’s my guide to some of the best:

Lilies are hardy, so can be planted outdoors now. Plant them deeply, at three times the height of the bulb, and position in full sun. They’re hungry feeders, so hit them with tomato feed fortnightly once you see signs of growth.

Begonias will give you long-lasting flowers, are brilliant for hanging baskets and window boxes, and so handy as they do well in the shade. To get the tubers started, place them sitting on moist compost. They usually have a concave hollow. This side should face upwards. Once green shoots emerge, you can pot them up individually.

Dahlia tubers can be potted now in damp compost and kept in a light, frost-free place such as a greenhouse, cold frame or windowsill. By May, your tuber will have produced lots of shoots and will be ready for outdoor life, but it’s a good idea to nip out a few of these and leave just five shoots. This will make the plant bushier and stronger.

Definitely different and quite exotic, Tigridia pavonia or the peacock tiger flower lives up to its name. Plant the bulbs 2cm deep with the pointed side facing upwards. These are tender, so keep them on a warm windowsill indoors until the risk of frost has passed.

If you like dark flowers, Zantedeschia Odessa is a sumptuous purple-black variety. Plant the tubers with the bumpy bits facing upwards in moist compost and move outside in May.

Nerine bowdenii will light up your garden in late summer and early autumn with its candy pink flowers. It’s hardy, so you can plant outdoors in late spring. These bulbs can be planted quite shallow in free-draining soil — the top of the bulb should just peep out from the soil. They seem to do best in their own company so grow them in clumps together.

Plant of the week

Chaenomeles x superba ‘Pink Lady’

Chaenomeles x superba ‘Pink Lady’
As a student in the Botanic Gardens in Dublin, there was always something in flower worth observing. Every spring, the simple wrought-iron fence around the director’s garden was covered in flowering pink and white quince. The quince, or Chaenomeles, had been trained around the straight bars many years before, and now shrub and fence were intertwined forever so that it appeared the fence itself was flowering. It can also be grown as a free-standing shrub but it can look messy. Grow in full or partial sun in a sheltered spot and prune after flowering.

Reader Q&A

I planted snowdrops in the green at this time last year. This spring, I see leaves but no flowers at all. What I have done wrong?
Jim

Snowdrops

The most common cause of ‘blind’ bulbs — those that don’t flower — is that they have dried out. This is one of the reasons planting ‘in the green’, as you did, is recommended. A different possibility is that you didn’t plant them deep enough. If this seems likely, now’s the time to dig them up and replant. I’d also give them a little feed to encourage them for next year. And sometimes, we just have to be patient, as some plants just take a little more time to settle into their new homes.

Submit your gardening questions to Diarmuid via his Instagram @diarmuidgavin using the hashtag #weekendgarden

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