Care of Spring-flowering Bulbous Plants

New Zealand Journal of Agriculture, Volume 79, Issue 3, 15 September 1949, Page 301

Care of Spring-flowering Bulbous Plants

DURING October the great majority of spring-flower-ing subjects will reach the height of their glory, such plants as wallflowers, forget-me-nots, polyanthus primroses, and tulips being in full bloom. However, toward the end of the

month most of them will have

passed the full flush of their beauty and will start to decline as they pass out of flower—indeed, the hyacinths and many of the narcissi already will be spent. With their passing the gardener is confronted with the problem of how to dispose of them so that the space that they occupied in beds and borders may be cleared and prepared in readiness to receive the summer-

and autumn-flowering subjects that should be planted out during the following month. Advice on this subject is included in this month’s article for the

flower gardener by M. J. Barnett, Director of Reserves to the Christchurch City Council.

SUCH plants as wallflowers and forget-me-nots are easily raised from seed each year and there need be no compunction about disposing of them in the compost heap, but tulips, narcissi, and hyacinths are too valuable and too hard to come by to be so ruthlessly destroyed,, and yet to allow them .to remain in ground required for succeeding planting until the foliage has ripened off would delay seasonal work too long. Therefore, to allow the work of summer planting to proceed to schedule, the bulbs must be lifted and heeled in somewhere else to complete the ripening off of the foliage.

Bulbous plants such as hyacinths, narcissi, and tulips start to develop root systems immediately they are planted out in late summer and autumn. In spring the leaves appear above ground and, with the lengthening of the days, rapidly reach their maximum growth. The flower heads appear in due course, and with their passing the leaves begin to fade gradually, though they continue to function for some weeks afterthat is, they continue to send down to the bulbs the food material or sap that has been elaborated in their tissues. To a large extent, the general health and flowering capacity of the bulbs for the succeeding year will depend on the supply of food material from the leaves. Therefore it is necessary that the foliage be retained intact as long as possible—in other words, until it has ripened off.

When the bulbs have to be lifted before this process has been completed certain precautions are necessary to offset the ill effects caused by this undue but necessary interference with the natural course of events. The bulbs should be lifted with the foliage intact and with as much of the root system as it is possible to obtain with ordinary care. Immediately after being lifted they should be taken to the reserve garden and properly heeled in. Failing a reserve garden or small nursery, any vacant piece of ground at the back of a shrubbery or a part of the vegetable garden will suffice. Once lifted, bulbs must not be exposed to bright sunlight or drying winds. If heeling in forthwith is not . convenient they should be covered with a damp sack in the meantime. To prevent the foliage from becoming unduly damaged and tangled with the bulbs, when lifted they should be placed in trays with the foliage laid out straight in one direction. Tulips require more careful handling than narcissi, as the foliage which envelops the flower stem at its junction with the bulb is very brittle and is easily broken off with rough usage. All flower heads that have

developed seed pods should be removed. Once heeled in, the bulbs can remain undisturbed until late summer, when they should be lifted, cleaned, and graded in readiness for next season’s planting. c d jj. rv i summer Deciding Displays If not already attended to, arrangements should be made not only for the supply of plants required for beds and borders but also for the scheme of planting contemplated. In , large establishments where many thousands of plants are required the bedding schemes are prepared 6 months and even a year in advance. Many amateurs depend on supplies from nurserymen, but even . when the plants required are obtained from outside sources the placing in advance of an order for the numbers and. kinds of plants desired is of advantage to both parties. When a planting scheme is being decided on several factors need to be taken into consideration. The first essential is to select types of plants that will succeed in the soil and situation. Some gardeners tend to try something new in place; of those of

proven worth; it is not intended to discourage such attempts, but if there is any doubt about the hardiness or suitability of the plants, it is better to make small trial plantings in the mixed flower border than to take the risk of using • them in large-scale display. Another point to decide when selecting the plants is the colour scheme. Some plants harmonise with each other and others are more suitable for contrasting;; for example, soft blue and pink harmonise well, and scarlet and yellow or purple and crimson provide good contrasts. When associating different types of plants the general characters of the subjects to be used should be . considered so that one kind does not appear incongruous. Having solved these problems, the next point is to estimate the numbers of plants . required to complete the planting scheme. ■ Finally, the aim should be to choose only plants or associations;, of plants that will provide a continuous display of colour throughout summer and autumn. Where the resources for raising successive batches of plants' are available a continuous display -of bloom, in the flower beds can be maintained by refurnishing them as required with fresh subjects specially raised in pots or containers, for the purpose, but because of the expense entailed such schemes are seldom, if ever, carried out in New Zealand. Examples of Bedding Schemes The following bedding schemes are submitted for consideration as examples, all of them having been carried out with success: — Scarlet geraniums with an edging of the white-leaved Centaurea can-.

didissima. If the latter is not procurable, the variegated edging geranium Madam Salroy may be used as a substitute. The white sweet alyssum Little Dorrit is also used sometimes, but it has the disadvantage of bolting to seed during dry weather and passing out of flower before the season is half over. . The orange-scarlet geranium Maxime Kavolisky with an edging/ of the golden-foliaged geranium Harry ■ Hieover. Other edgings that may be used to advantage are lobelia Cambridge Blue or Echeveria secunda. The pink ivy geranium Charles Turner with an edging of • Cambridge Blue lobelia. If extra height and variety in the beds are desired, fuchsias, ivy geraniums, and heliotropes may be grown on, trained as standards, and planted about 3ft. apart through the geraniums. A standard fuchsia such as Ballet Girl would be planted with the scarlet geraniums, Garten Meister Bonstedt with Maxime Kavolisky, and standard ivy geraniums or heliotrope with the Charles Turner. The bedding dahlia Bishop of Llandaff with an underplanting of delphinium Blue Butterfly, which may also form the edging. Dwarf ageratum may be used for edging. Any of the good yellow miniature cactus dahlias such as Tip with an underplanting and edging of blue verbena. Petunia Pink Bedder with an edging of ' petunia Dwarf Violet. African marigold Double Orange with an outer row of the dwarf Crown of Gold and an edging of the dwarf Tagetes signata pumila.

French marigold Harmony with an edging of the dwarf variety Spry or Legion of Honour. Many , other schemes are worth consideration. Antirrhinums may be procured in a wide range of colour. There are 'four distinct classes of these plantsthe . majus or tall varieties, which are excellent for grouping toward the backs of flower borders; the intermediate or nanum varieties, including the majestic and grandiflorum strains, which are most suitable for bedding purposes, and the bedding varieties, which may also be used by themselves in small beds, for underplanting beneath dahlias, or as an edging for large beds; and the Tom Thumb varieties, which because of their dwarf habit are admirably adapted for edging purposes. Nemesias may be planted throughout and among antirrhinums to provide a display of colour until the antirrhinums come into bloom, by which time the nemesias will have passed over and can be removed. The following is an example of how flower beds were maintained in full bloom from November to the end of April: Dahlias were first planted at 2-> to 3ft. intervals; intermediate antirrhinums were planted at 12 to 15in. intervals, through the dahlias, followed by nemesia between the antirrhinums, with Tom Thumb antirrhinums as an edging. The planting was carried out simultaneously, and the colours of the antirrhinums were chosen either to harmonise or to contrast with the colour of the dahlia. The nemesia came into bloom toward the end of November and carried on a display until January, by which ■ time the antirrhinums were in full flower. By the middle of February the' dahlias were making a good display, which was maintained until they were cut down by the early frosts of late autumn. If the seed heads are

removed from the antirrhinums at the outset, they also will continue to flower.

In preparing beds and borders for planting, some attention to the requirements of the plants to be used is advisable. Dahlias, for instance, respond to liberal treatment, and ground where they are to be grown should be generously treated with organic manure beforehand. On the other hand, in such conditions geraniums would make too much rank, soft growth at the expense of flower production, so where these plants are being used it is customary not to apply any manure before planting except perhaps a light dusting of superphosphate at a rate of not more than loz. per square yard. To make up for the deficiency in organic matter, such beds are manured in the autumn before spring-flowering subjects such as the polyanthus primroses are planted out, whereas beds manured in spring for dahlias are not so treated in autumn and are used at that season for the planting of wallflower or tulips.

Pruning of Shrubs

.As • soon as the spring-flowering shrubs such as forsythias, spiraeas, and deutzias have passed out of flower they . should receive their annual pruning. With the rush of work at this time of the year this operation is too frequently overlooked, with the result that in time the bushes become untidy, tangled masses of old and spent wood intermingled with the younger growths. For example, a study of the growth and habit of the forsythia shows that a number of leading shoots develop from near the base of the bush and from the lower parts of the old wood. During spring these' growths . (the previous year’s wood) produce numbers of flowers along the stems. If left undisturbed in the following season, a number of lateral or side growths . will develop from these stems, and these in turn will bear quantities of bloom in ’ spring. However, if the stems are left for a third season, the lateral growths become shorter ! and fewer ; and serve only to clutter up the bush and . prevent the production and proper development of young, strong growths which should replace the old ones.

Therefore, the object of pruning

immediately; after flowering is to remove as much as possible of the old wood that has flowered in order to make room for and encourage the growth of young and more vigorous shoots that will

supply more bloom for the coming spring. : .

Such subjects as almonds, prunus, and peaches may also be pruned at this time of year, but in these cases the operation is restricted to removing decayed, , damaged, and unwanted wood to keep them healthy, balanced, and well proportioned.

If necessary, evergreens such as camellias, rhododendrons, and hollies should be pruned at this season. In general, such plants require little attention, but on occasion restricting their growth or improving their shapeliness may be necessary, in which

case October is an opportune time to attend to this work so that the bushes will have ample time in which to recover - and. develop fresh growth before the approach • of next winter. Winter- - and early-flowering ericas should also .be . pruned now, but they, must not be cut back to the old wood. The general practice is to cut them’ back below the flower head to where: : young growths are starting. The dwarf, bushy types such as Erica carnea can be dealt with quickly by tipping them lightly with shears. . Lawns . < A close, well-kept lawn of even• texture is always admired. To achieve •this objective lawns : should be cut regularly . and frequently at this season, for if the grass is allowed to get slightly out of ■ hand, now, it will prove difficult to bring • 'back to an even turf for the rest of' the season. The grass catcher should be kept on; later in summer when growth has slowed down it can be dispensed, with if need be. To stimulate the finer grasses, assist in the eradication of weeds, and discourage the growth of clovers and some of the coarser grasses, one or two applications of sulphate of

ammonia may be made either in dry powder form or as a solution. The powder form should be used on a morning when a heavy dew lies on the grass and which presages a fine sunny day, the chemical being distributed evenly over the whole surface at the rate of loz. per square yard; The granules'of powder will alight on and be held and’. dissolved by the beads of moisture on the foliage; the hot sun beating " down :on to the acid solution thus formed; will have a burning affect on the .flat,' fleshy leaves of such weeds as the lawn daisy, dandelion, plantain, and catsear. It is not claimed that one application will destroy the weeds, 1 but it is sufficient to check their growth and to encourage the finer grasses to smother them. A second application within 10 days or a fortnight will prove even more effective. . J .;’ i. If a lawn is badly infected with .weeds and the grass' lacks a good green colour,, or where moss is present, sulphate of iron can be mixed with the sulphate of ammonia at the rate of 1 part of sulphate of iron to 4 parts of . sulphate of ammonia. This mixture is more drastic in action and has a decided bleaching effect on the grasses, which, however, recover rapidly and become a much deeper green within a fortnight of treatment.

The weedkilling hormones now on the market are advocated for eradicating weeds from lawns. Though excellent for this purpose, they do not feed or in any way promote a better growth of the finer grasses, and they must be used with the greatest of care. The slightest particle of the spray alighting on plants adjoining or flanking the lawn may prove disastrous to them. Moreover, the spraying apparatus or container used must be thoroughly washed out many times before it can be used for other purposes. If hormones are used, to be on the safe side it is better to keep one spray can entirely for that purpose. Sulphate of ammonia and the mixture of sulphate of ammonia and sulphate of iron are both more effective when sprayed on the lawn as a solution6oz. of sulphate of ammonia and '2oz. of sulphate of iron dissolved in 1 gallon of water or if only sulphate of ammonia is used, Boz. of it to 1 gallon. To ensure that the solution is spread evenly over the lawn it is a good, plan to divide the grass into 3ft. strips with a garden line. One gallon of the solution will spray 16 sq. yds. The texture and general appearance of a lawn can be improved further by raking the surface with a steel rake before mowing it. Plants to Propagate For late summer and autumn flowering, hardy annuals such as clarkias, goaetias, sweet peas, and nasturtiums may still be sown in open ground as advocated in last month’s “Journal.” It is not too late to sow half-hardy annuals such as African and French marigolds and zinnias. Zinnias grow rapidly and are very susceptible to cold winds. If they are sown late, kept growing without a check, and planted out in December when the weather is more settled and warmer, they frequently succeed better than those planted out a few weeks earlier. Asters for late flowering may still be sown both under glass and in the open.

Primroses and polyanthus primroses required for spring displays next year can be sown this month. As soon as they are large enough to be handled the seedlings can be pricked off into boxes or seed trays and grown on until ready for planting out in the open in March and April to flower during the following September and October. For providing displays of flowers in a greenhouse during, winter, sowings should be made of Primula malacoides, P. sinensis, P. obconica and cinerarias. Cinerarias germinate freely in normal circumstances, but primulas require more care. A simple seed compost to use is equal,parts of sweet loam . and leaf mould, well mixed, with sufficient clean, sharp, river sand added to keep it open. Five-inch or 6in. pots are a suitable size, and they should be well crocked to provide drainage. To prevent the finer compost from being washed down into them, the crocks should be covered with some rough material such as riddlings, sphagnum moss, or spent hops. The compost is then made reasonably firm but not hard, and finished off with a level and even surface to within fin. of the rim. Stand the pots in a basin of water until the moisture begins to show on the soil’s surface. Then remove them and, after allowing the surplus water to drain off, sow the seed thinly and evenly, just covering it with a sprinkling of sand. Cover each pot with a piece of glass shaded with brown paper; the object of the glass is to prevent rapid evaporation of the moisture from the soil and that of. the paper to exclude strong light, the paper being removed during darkness. Each morning the glass should be lifted, the condensed moisture removed, and the glass replaced. An endeavour should be made to maintain an even temperature of about 55 degrees F. As soon as the seed germinates freely the glass and paper should be removed, but care is still necessary. The seedlings should be lightly shaded from strong sunlight, and draughts and sudden fluctuations in temperature avoided.

War on Weeds Weeds will be growing apace and at every opportunity means should be taken to combat them. The flat or dutch hoe is one of the best implements to use; correctly handled, it severs the weeds from their roots just below the surface and effectively stirs the surface of the soil. Nevertheless, its use in herbaceous borders is not advocated, as too frequently considerable damage is done to plants there by its injudicious use. The garden fork is a much better implement to use in such places; there is little fear of the crowns of plants or their young shoots or roots being cut and damaged by it, and it breaks up the surface soil more effectively. The common practice of hoeing over a border and allowing the -weeds to remain and wither away on the surface is difficult to avoid in large gardens where time and cost must be considered, but in the home garden the weeds should be removed. Such weeds as groundsel, shepherd’s purse, ground cress, and chickweed even when cut over have sufficient sustenance left in them to ripen seeds which have already formed. Once ground becomes infected with chickweed many years of weeding are needed to eradicate it. Though it is only an annual, it is a prolific seed bearer and, as the seeds . are viable in the soil for many years, if it is allowed to bear seeds but once, seedlings will continue to appear for many years afterward. Herbaceous Perennials Herbaceous perennial plants will be making strong and rapid growth and will . require- immediate attention. Some, such as perennial phloxes and asters, may have produced too many young shoots and will require thinning out. Select from 5 to 7 of the strongest and most likely shoots and remove the others. Other plants, because of the nature of their growth, will require some support to prevent their being blown over by wind or beaten down by heavy rain. . Staking may be considered to be an evil, but nevertheless it is necessary and must be attended to in good time.

Plants Recommended by the District Council of the Royal New Zealand Institute of Horticulture for Planting in the Auckland District

Evergreen Native Trees Deciduous Trees Herbaceous Plants Annuals and/or Biennials Alectryon excelsum (titoki) Paulowma imperiahs Melianthus qucrtifoli-iis Autumn tfrxwnm Podocarpus totara (totara) Liquidambar styraciflua Glory ixcmesta st, umosa , Metrosideros tomentosa (pohutu- Fagus i vat i ca purpurea riversi Helenium Riverton Gem Petunia Pink Bedder kawa) (M. excelsa) (copper beech) Carnation, Andrew Nicol Marigold Harmony IT agates') Evergreen Exotic Trees P && jamesoni . ' Salvia Bonfire . Scabiosa columbaria Cupressus lawsoniana aurea Exotic Flowering Shrubs Salvia patens Statice sinuata (Limonium Quercus ilex . , . Agapanthus umbellatus sinuatum) Eucalyptus ficifoha . Azalea rndica Strelitzia reginae 7 Magnolia grandiflora Cestrum newelli (Habrotham- Canna indica ■ ' Eugenia myrtifolia nits') Chrysanthemum Esther Reid Alnine Plants .. .. _. , Magnolia stcllata Aipine riants Native Shrubs Luculia gratissima Phebalium nudum . Prostanthera ovalifolia Bulbous Plants * ,c ,ar ac 0 acn Leptospermum' scoparium Protea Susanne Nepcta mussini . keatleyi Polygala grandis (P. oppositi- ■ Frccsia burton! Convolvulus ' mauritanicus Pittosporum eugemoides (tarata) folia') . Lachenalia pcarsoni (Tbomnm Sophora tetraptera (kowhai) Rhododendron fragrantissimum Narcissus Solei! d’Or (ippmaeai anti . anicus) (Edwardsia grandiflora) Tibouchina grandiflora ■ Nerine filifolia .Campanula garganica . Veronica spccidsa (Lasiandra) Lilium forniosum Dianthus species