Christmas. There, I’ve said it. Or rather, I’ve written it. Yes, yes, my apologies for using the C word given that we’ve yet to celebrate Halloween but such is the world of gardening, where pretty much everything is done with one eye to the future. So if your mind is filled with thoughts of pumpkins, toffee apples, fireworks and bonfires, forgive me because I’m now going to do my best to fill it with thoughts of Christmas flowers. Oops, sorry, there I go again, but there really is no other way if I’m to write this particular column in a timely fashion.
I say timely because while it’s entirely possible to grow an array of beautiful blooms to decorate the home during the . . . erm . . . “festive season”, it does require a certain degree of forward planning. Plants, after all, need a slice of time to put down roots, grow leaves and produce their pretty flowers, even the most obliging, fastest-growing kinds capable of miraculously blooming indoors in the dead of winter when light levels are at their lowest.
In particular I want to talk to you about paperwhites, a type of frost-hardy daffodil or narcissus, whose tall, deeply perfumed, multi-headed ghostly white flowers can fill a room with their scent. Planted within the next couple of weeks as bulbs suitable for “forcing” – the horticultural term for fast-tracking a bulb into early flower – they make a beautiful and elegant addition to the Christmas table or a lovely gift for the flower-lover in your life.
The classic variety is Ziva which is well known for its strong fragrance. But if you prefer your flowers with a slightly more subtle perfume, then look out for Inbal, a very floriferous variety with a more delicate scent and sturdier stems. Others include Nir, Ariel, Galilee and the yellow-cupped Winter Sun. Whichever you choose, do your best to source large, plump, blemish-free bulbs. Recommended suppliers include good Irish garden centres and garden shops such as mrmiddleton.com as well as specialist online suppliers such as UK-based peternyssen.com and sarahraven.com (via ParcelMotel).
To grow these sweetly scented beauties, you’ll need a bag of good-quality loam-based compost lightened with a little horticultural grit plus a pot or decorative container. Shallowish bowls or troughs are also fine as long as they provide sufficient room for these bulbous plants’ root systems, which don’t go down much below 8-10cm.
To start, spread a shallow layer of grit at the base of the container before adding a layer of the gritty compost mix. Plant the bulbs very close together but not touching, with their pointy ends up, their flattened basal plates (the part from which the roots grow) facing down, ideally in groupings of 5-7 bulbs and at a depth where the tips are just above the surface of the compost, then water gently.
Alternatively, you can completely forgo the use of compost and plant your paperwhite bulbs into a handsome watertight container, vase or bowl, burying them up to shoulder height in ornamental gravel/ small stones/ glass chippings/ aquarium pebbles or even marbles. Then carefully add water so that the finished level barely touches the bottom of the bulbs. Any more and it will make them rot. Bear in mind that this method suits only certain varieties such as Ziva while others such as Inbal are much better grown in a loam-based compost.
The next step, whether you’re using compost or water as a growing medium, is to place your freshly planted container somewhere cool, dry and away from direct sunlight (ideally around 10-15C). Steady, even growth should be the aim. Wait until the buds begin to appear then move it somewhere very bright and reasonably warm but not broiling (ideally around 18C). If you’re growing your bulbs in compost, keep it damp but not sodden. If you’re growing them in water, keep it topped up just to the recommended level (barely touching the bases of the bulbs).
Now the trick is to control growth levels/ exact time of flowering by monitoring the amount of heat and light that they receive. The less light you give them, the taller the flowers and foliage will be to the point where they’ll quickly become floppy. The warmer and brighter the room, the faster they will flower, but avoid placing them somewhere very hot and dry as this can stop the flowers from developing. You can also slow down flowering by moving the container somewhere cooler (this will also help the blooms last longer).
Intriguingly, scientists at Cornell University proved that the old folk wisdom of adding spirits to the water at a dilution of seven parts water to one part gin, vodka, whiskey, rum, tequila (to give a solution of no more than 4-6 per cent alcohol) was extremely effective as a means of preventing water-grown paperwhites from becoming too leggy. But be warned that beer or wine are not suitable (too sugary) while this alcoholic bevy should be administered only once the plants show obvious signs of active growth.
A simpler method is to use a low latticework of artfully placed twiggy branches as a scaffold to help to support their tall flower stems as they stretch out. Wise gardeners stagger their bets (and the pleasure to be had from these bulbous plants’ ethereally beautiful flowers) by planting up several pots at once but bringing them into the heat and light in batches spaced days/ week(s) apart.
This way, you never have the dilemma of having too much of a good thing.
This Week in the Garden
Check established trees and shrubs for signs of damage as a result of the recent storms. Large, partially broken branches left dangling at a height pose a particular risk to life and limb as well as to buildings and garden structures, and will need to be professionally removed by a qualified and insured arborist or tree surgeon. Also check young, recently planted trees and shrubs for root rock as a result of the recent high winds, using your foot to firm back the soil. If planted in a very exposed spot, consider staking.
Continue to plant spring flowering bulbs as long as soil conditions haven’t become too wet/ unworkable as a result of the recent heavy rainfall. To create successional displays of spring colour in a container or bed, use what’s known as the “lasagne method”, where you plant in dense layers starting with the largest, last-to-flower bulb varieties to the bottom (for example, mid to late-season tulips and narcissus) and the smallest, earliest-to-flower bulb varieties to the top (examples include scillas, chionodoxa, crocus, Iris reticulata, grape hyacinths,), with roughly 4-6cm of good-quality multipurpose compost between each layer of bulbs and using no more than three layers. Before planting any container, always make sure that it has a sufficient number of drainage holes as otherwise bulbs and plants will slowly diorite over the winter.
October is the best time to either move or plant peonies. Give these exceptionally beautiful and long-lived plants a deep, fertile, moisture-retentive but free-draining soil enriched with plenty of well-rotted manure and few handfuls of organic granular fertiliser plus some horticultural grit to improve drainage if the soil is on the wet/ heavy side. Utah hybrid and herbaceous types of peonies need a spot in either full sun or light shade and should always be planted shallowly so that the bud (the top of the plant crown) is no more than 1-2cm beneath the surface. Tree peonies will tolerate deeper shade and should be planted at a sharp angle (almost horizontal) and to a depth where the graft (visible as a join between rootstock and the rest of the plant) is at least 8cm below ground. For a specialist supplier of peony plants, see Wicklow-based leamorenursery.com.
Dates for your diary
Wednesday, October 24ah, 8am: Airfield Estate, Dundrum, Dublin 14, "Irish Horticultural Heritage", a lecture by Blarney Castle's garden manager Adam Woodburn on behalf of the RHOS, admission €10 for non-RHOS members; student €5, see rhos.ie.
Tuesday, October 23red, 8am: Foxrock Parish Pastoral Centre, Kill Lane, Dublin 18, "Hellebores a Friends", a lecture by Dr Julian Sutton of UK-based specialist nursery Desirable Plants on behalf of Foxrock District Garden Club, see foxrockgardenclub.com