Forcing Dutch Iris Bulbs – Learn About Dutch Iris Forcing Indoors
The following are some tips for forcing your own Dutch irises indoors:
1) Do not use a light bulb with mercury vapor in it.
These bulbs do not produce enough heat to kill the insects inside them. You will need to purchase a non-toxic bulb (e.g., incandescent).
2) Place the bulb into a glass jar filled with water.
If possible, place the jar in a sunny location so that the sun’s rays will warm up the water. If you cannot obtain a non-toxic bulb, then just make sure to keep your room at least 75 degrees Fahrenheit during winter months.
3) After placing the bulb into the jar of water, cover it completely with plastic wrap or aluminum foil.
Then leave it out overnight.
4) In the morning, remove the plastic wrap or foil from around the bulb and shake off any excess moisture.
5) Next, place a small amount of water in a cup and add 1/8 teaspoon of dishwashing liquid.
Use this solution to rinse away any dirt or dust that may have collected on top of the bulb. Repeat until all traces of dirt have been removed.
6) After cleaning the bulb, you may place it on a saucer or tray filled with potting soil.
If you want to see roots in the shortest amount of time, make sure that the bulb is just beneath the surface of the soil. Remember to place the bulbs in a well-lit area that stays around 75 degrees Fahrenheit.
7) Check for roots in two weeks.
If you see a short white root coming from one of the “lobes” on the bulb, then it is time to plant it into a container filled with potting soil.
As you can see, it is fairly easy to force Dutch irises indoors if you follow a few simple steps. If you want more detailed information on particular steps listed above, please consult your local gardening center. The experts there should be able to help you out.
Should I Deadhead Dutch Iris?
Here is what Wiki-pedia says about Deadheading: Deadheading is the removal of the spent blossoms of a plant, either regularly or when they have died before the seeds are mature. The term refers to a particular species or cultivar, not a general practice of all flowering plants; it is most often used in the context of maintaining ornamental plants.
Most plants that bloom on old wood (last year’s growth) should be deadheaded. This improves the vigor of the plant and often improves the next years blooming as well.
Deadheading not only encourages new flowers, but keeps the appearance tidy and can prevent unwanted seeding. It is also a great time saver as many perennials would require frequent cutting if they were not deadheaded. Deadheading can extend the life of some plants such as tuberous begonias and daylilies so that you are rewarded with flowers even in the autumn months.
When to Deadhead
Most plants that bloom on last years growth should be deadheaded. This is common practice for annuals and perennials. Deadheading can be a tedious task, especially with larger plants such as hollies or wisteria, but it can keep a plant from looking messy, keep it from expending energy on seed production and extend its blooming season.
Besides tidiness, deadheading has other benefits. Some plants such as dahlias, zinnias and cosmos do not produce seed until their flowers have been pollinated. If you do not want these plants to reseed or do not want the seed produced, these plants should be deadheaded before the seeds mature. This can be somewhat difficult with some plants such as paperwhites and narcissus, but it can be done if you are willing to spend the time.
Some plants such as lilies and gladiolus have such complicated flowers that their pollen is less likely to be transported by insects. These plants can produce a surplus of seeds that will become entangled in your clothing or wash off into the garden bed. Deadheading these types of plants will help prevent this problem.
How to Deadhead
Deadheading can seem like a daunting task, but it does get easier with practice. Here are some tools to make deadheading easier.
Scissors – A good pair of household scissors is one of your best weapons against deadheading. Use the scissors to cut the flower at the base of the stem or use it to cut the stem off close to the soil line.
Knife – A sharp knife can make quick work of deadheading. As with the scissors, cut the stem directly above the root system.
Clippers – Some plants such as hollies or wisteria have very thick stems that are difficult to cut with household scissors or a knife. For these plants, clippers can make deadheading easier.
When using any of these tools be very careful not to damage the plant by cutting into a branch or the main trunk. Deadheading can be very time consuming, especially for large plants such as climbing roses or yews. Deadheading can take away from the enjoyment of your garden, so pick your battles.
You don’t need to deadhead every flower, if it isn’t spoiling the appearance of the garden, leave it for next year.
Deadhead plants that bloom on old wood before new growth starts. Some plants such as peonies will be more difficult if not deadheaded before new growth starts.
Deadhead any time a flower has faded, but do not remove fresh flowers. Removing the old flowers will prevent the plant from wasting energy on seed production.
Some plants such as coreopsis or blanket flowers will produce a second round of flowers if deadheaded before they are completely spent. If you are deadheading for neatness, wait until the first round of flowers is spent before deadheading.
Weed the area around your plants as they grow. Weeds will steal nutrients from your flowers and vegetable plants as well as sunlight.
Use a grasscatcher when mowing to keep grass clippings from building up around your plants. Build up of grass clippings can suffocate the roots around the base of your plant.
Do not apply fertilizer until after you have finished harvesting your flowers. Apply a slow-release fertilizer such as 5-10-5 or 8-16-8 at the beginning of the growing season if you notice deficiencies in bloom or growth.
Deadheading is one of the chores that most people dislike, but it is an important step in keeping your garden healthy and producing beautiful blooms. By deadheading regularly you will encourage more flowers to grow and keep your garden neat.
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Sources & references used in this article:
Effects of ethylene action inhibitors and ACC on induction of flower buds of Dutch iris cv. Blue Magic by D Yue, H Imanishi – V International Symposium on Flower Bulbs 266, 1989 – actahort.org
Fooling mother nature: forcing bulbs for indoor bloom by AA De Hertogh, M Le Nard – The commercial storage of fruits, vegetables, and florist …, 2004
Fooling Mother Nature: Forcing Flower Bulbs for Indoor Bloom by K Whiteside – 1999 – Workman Publishing
Effect of light and growth substances on flowering of Iris x hollandica cv. Wedgwood by G Graine, H Scoggins – 2019 – vtechworks.lib.vt.edu
A review of ethylene effects in bulbous plants by G Graine, HL Scoggins – 2014 – vtechworks.lib.vt.edu
The early-forcing of daffodils by T Mae, CR Vonk – Acta botanica neerlandica, 1974 – natuurtijdschriften.nl
The growth of bulbs: Applied aspects of the physiology of ornamental bulbous crop plant by GA Kamerbeek, WJ De Munk – Scientia Horticulturae, 1976 – Elsevier
Landscaping with Bulbs: Storey’s Country Wisdom Bulletin A-99 by E van Slogteren – 1938 – library.wur.nl