White Starflower in containers
LAsagna Layering with Summer Bulbs


bulb
10in (25cm)
14in+ (35cm)
white
Mar-Apr
full/part sun
average soil
scented

White starflower (Ipheion uniflorum ‘Alberto castillo’) is certainly star of my garden in March. The pot above is on the patio right outside my kitchen door where I see it every day. Its bright showy flowers are 1.5 inches across (4cm) and held six inches above the narrow bright green foliage that emerges in early winter. As you can see in the photo above, the lax foliage is very healthy and beautiful in its own right. It makes a great feature at the front of the border or in an alpine rock garden. However, it has particular potential in pots and containers which is what this article is all about.

Unlike other spring bulbs such as daffodils and hyacinths which only flower for a couple of weeks, Ipheion will flower for nearly two months, putting out new buds over a long period. Another difference is the foliage which emerges in late autumn and looks good throughout the winter and spring. This is a bonus as few plants are actively growing and looking good at this time of year. The plant is related to the onion family, with the leaves having a garlic scent when crushed. The flowers, however, are sweetly scented and attractive to bees and other pollinators. Wild Ipheion uniflorum is a very pale blue, while several named cultivars claim various deeper shades – although the ones I have seen are a little washed for my tastes; To my eye, the pure white versions like ‘Alberto castillo’ are particularly classy.

Ipheion can be purchased as bulbs in the autumn, although sometimes you can find it in nurseries with the alpines or spring bulbs as a small clump growing in a pot. Planted in a free-draining sunny spot, Starflower grows quickly, bulking up in a few years. Once they become congested, clumps can be divided and potted up or planted in other areas. The individual bulbs are small, being just 1cm across and are particularly cheap when available online. Once they get going they multiply readily which can lead to them becoming invasive in some situations, but this is less of a problem when grown in a container.

starflower with other bulbs

Layered Planting in Pots

After flowering, the starflower’s foliage remains for another month or two, gradually dying back as the bulbs enter summer dormancy. New foliage emerges again in late autumn. It is possible, therefore to underplant the Ipheion with bulbs or perennials that will emerge when the Ipheion has finished which will then flower while the Ipheion is dormant, giving the container two flowering seasons.

The idea of layering bulbs to extend the flowering season has been termed ‘Recently, the idea of layering bulbs in pots to extend the season has been given the name ‘Lasagne planting’.

Two such plants I am experimenting with are dwarf dahlias and pineapple lilies (Eucomis). Both of these plants emerge very late in the season, typically only pushing up leaves towards the end of May, by which time the Ipheion will have died back. In the past I have planted annuals such as pansies and cyclamen and ranunculus to make use of the bare soil in these pots, but I like the idea of having a low-maintenance perennial instead.

Ipheion seems an ideal candidate as it sends up new leaves in mid to late Autumn – around November in my garden. So, as long as I cut back the old stems of the Dahlias and Eucomis by then, the two should be able to co-habit indefinitely. At least that’s the theory!

Layered planting in a large pot of Starflower (Ipheion bulbs) over dwarf Dahlia tubers or Pineapple lily (Eucomis)

Dahlias and Eucomis overwinter in pots in my garden because they are sufficiently deeply buried. The dahlia was planted with at least four inches of compost over it and the Eucomis closer to five or six inches. This leaves plenty of space for the much hardier Ipheion bulbs which are happy with just an inch or two of soil above them.

The arrangement may also work with lilies (Lilium) which emerge a bit earlier in the season, probably before the Ipheion has died down. However, many lilies have quite narrow, open foliage which will probably not rob too much light from the starflower leaves. I may try this combination later this year.

As an experiment I have planted Ipheion bulbs in the top of a pair of dwarf dahlia pots and two pots of Eucomis ‘Autumn White’:

I planted the Ipheion bulbs rather late in the season, which may explain why they have not flowered this year, but you can see their leaves are strong and healthy, covering the top of these otherwise bare pots. Hopefully they will cohabit peacefully with their summer-flowering partners and this time next year be covered in flowers like the pot at the top of this post.

UPDATE: SUMMER 2022

As you can see, below, the Dahlia and Eucomis bulbs grew well, unaffected by the Ipheion which had died down naturally by this time.

The question is: did the Ipheion bulbs have enough time to bulk up before they were shaded out? I think so, as both Dahlia and Eucomis emerge late in the season… we will see.

UPDATE: SPRING 2023

A very long cold spring meant that the main pot of Ipheion came into flower much later than previous years, but by March was in full swing. The foliage was somewhat battered by freezing winds and repeated late frosts. Compared to the photo at the top of this post, you can see that the bulbs have bulked up.

The same pot of Ipheion ‘Alberto Castillo’ in March 2023

The Ipheion planted in the top of the Dahlia and Eucomis pots flowered well too. They are only a year old but are bulking up nicely. They clearly work well sharing a pot with late-emerging summer bulbs really extending the season and making the most of these planters. The only concern I have is whether the Dahlias and Eucomis have survived the harsh spring.

UPDATE: Autumn 2023

It turned out that one of the two Eucomis pots survived fully, but the other only produced one pineapple lily (the other bulbs presumably having succumbed to cold). I may buy some more Eucomis bulbs and try planting them through the Ipheion next spring. Should be interesting, as it will mean lifting a section of Ipheion before they die down, planting the Eucomis, then putting the Ipheion back on top.

Both of my Dahlia pots failed, which is surprising as they had survived in the same spot for the previous five or six years. That’s what an unexpectedly hard winter can do I guess. In May, I planted white annual Cosmos in the pots. This required me to dig some holes which I did by pushing the Ipheion aside. The Cosmos flowered well all summer, and (as you can see below) caused no problems with the Ipheion flowering the following spring.

In future, I may place the pots under cover (in my unheated greenhouse) in December, and only bring them out in March once the Ipheion are in full swing.

UPDATE: SPRING 2024

Spring was mild, but February was the wettest on record. The main pot of ‘Alberto Castilo’ has done well, as have the Dahlia and Eucomis pots.

The same pot of Ipheion ‘Alberto Castillo’ in March 2024

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