Broersen Bulbs

Pty. Ltd.

Specialist Bulb and Flower Growers

 

 

Growing guide

GROWING BULBS IN POTS FOR INDOORS

Many types of bulbs can be forced successfully in containers, the most favourable and reliable being spring flowering bulbs such as Hyacinths, Tulips, Daffodils, and Jonquils. With a little effort the results are very rewarding.

We encourage commercial growers who are looking to grow potted bulbs to contact us for advice as individual circumstances and growing location/climate should be taken into consideration.

SELECTING POTS: Any type of pot, trough or other container is suitable provided they are at least 12-15cm deep. Ensure they have adequate drainage holes in the bottom.

SOIL FOR FORCING: A good quality general purpose potting mix is recommended. Some manufacturers also produce a mix that is tailored for bulbs, which is also suitable. A good quality mix should already contain the nutrients required for feeding. Keeping in mind that bulbs have their own food supply, there is no need to feed them excessively.

PLANTING TIMES: Tulips and Hyacinths should be planted no earlier than Anzac Day (April 25th) in cooler areas, and if conditions are warmer at this time or you are in a warmer area, delay planting until around Mother’s Day (early-mid May). Daffodils and Jonquils can be planted from early April. The optimum overnight temperature at this time is 5°C or lower for potted bulbs.

PLANTING: Only one variety of bulbs should be planted to each pot. This way all bulbs in the pot will flower together. In larger tubs or troughs, plant in small groups of a single colour. When planted in pots, bulbs can be spaced as close as 1-2cm apart.

Initially fill pots about halfway, gently pushing the bulbs into position. Once the bulbs are in position, add the remainder of the potting mix, firming this around the bulbs until the soil level comes to 1/2 cm below the rim. There should be a minimum of 2cm of soil above the tips of the bulbs and a maximum of around 12cm. Water well until all the soil is moist.

AFTER PLANTING: The potted bulbs now need a cool growing period to allow them to develop roots, stem and bud, and must be stored using one of the following methods:

Home Gardeners: The common method is to place the pots in a cool, dark position such as under the house, in a dark, shady area, in a cupboard inside the garage or similar. To ensure complete darkness, pots can be covered with a large paper bag. The soil should always be kept moist, but not too wet. The second method is to set the pots into a well drained position in the garden and cover with 5-8cm of friable soil.

Commercial Growers: Keep pots in a cool spot in shade, preferably out of sunlight to keep the pots cool and allow the roots to develop. Too much heat or light during this stage can cause shortened growth and stunted flowers. It is important not to plant the bulbs too early. See above for planting times.

After about 8-10 weeks, or when the shoots have reached a height of around 6cm, the pots can be moved to a slightly warmer, semi-shaded area. The pots should then be gradually returned to full light and warmth over a period of approximately 5-10 days. Home gardeners who have set their pots in the garden and covered them with soil, can wait until closer to flowering time or when buds begin to show before moving pots.

Pots should be kept cool and moist at all times.

FLOWERING: For home gardeners, temperatures between 18-22 deg. C. are recommended for maximum flower life. Keep away from heaters and draughts. When placed near a window, pots may need to be turned occasionally to keep flowers erect.

Commercially potted bulbs are ready for sale or use when the buds begin to show some colour and before opening. This will ensure maximum flower life for consumers and avoids damage in transport.

AFTER FLOWERING: Move pots outside to a shady position and cut off the dead flowers. Keep soil moist until the foliage has died down. Bulbs can then be removed and should be planted out in the garden the following season. Forced bulbs will not flower indoors two years in succession.

EXTRA NOTES FOR COMMERCIAL GROWERS:

For bulbs that have been pre-cooled, these can flower up to 6-8 weeks earlier than their usual flowering period. Pre-cooled bulbs should be planted no earlier than early May. Information about pre-cooling bulbs is not provided here, however if you are interested in obtaining further information on this subject, please contact us.

Once the tips of the bulbs have emerged, it is important to watch for signs of Botrytis (a fungal disease) as control is important. It is a good idea to start spraying regularly (every 1-2 weeks) with a fungicide at this time and throughout their growing period, particularly if their growth has been exposed to extreme weather conditions or hail.

Growers are encouraged to contact us at anytime should you have any queries or if any problems arise and you are not sure what treatment is needed. Most issues if managed quickly can be rectified.

Please note that this information is provided as a guide only. As growing conditions are beyond our control, we cannot be responsible for the crop.

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