Understanding different flower stem types

Gain Knowledge from the Experts

Whether you are cutting flowers and foliage from your own garden, or simply love flowers and want to get the very most from them, an understanding of different stem types is very helpful.

Commercial grown flowers are specifically breed, selected and conditioned to last well. The advice given below is useful knowledge for all flowers, but it is especially beneficial for home grown stems, as many garden flowers require some additional preparation after cutting.

Conditioning involves the preparation of cut plant material prior to its arrangement, to ensure that its life is not unduly shortened. Correct conditioning will make sure that flowers and foliage last for the maximum time, providing the most value and enjoyment.

Plant material should be conditioned according to its stem type, and conditioning varies with different stem types: hearty, hollow, soft, woody, or milky.

Hearty Stems (or solid) stems
Examples Celosia/Cockscomb, Clarkia, Marigolds and Statice.
The Hearty or solid stems need only the diagonal cut to absorb maximum water. They should be left to drink in lukewarm water with preservative for a minimum of one hour before arranging.

Hollow Stems
Examples Delphinium, Lupin, Amaryllis, Mollucella/bells-of-Ireland, Dahlias, and Hollyhocks.

The stems of hollow-stemmed flowers, such as, need to be filled with water, most commercially grown hollow stemmed flowers are grown for their suitability to draw the water up the stems naturally. Garden cut hollow stemmed flowers can be notorious for forming air-locks, as air enters the stem as soon as it is cut. To avoid this cut the stems at an angle and remove lower leaves as usual. Simply turn the flower upside down and fill the hollow stem with tepid. To keep the liquid in, you can plug the stem with a small piece of cotton and then place it in the vase or place your thumb over the opening at the bottom of the stem and then put it in the water. The water trapped inside will keep the stem strong and straight. 

Bulbous Stems 
Examples Daffodil, Iris, Tulips and Hyacinth.

Most bulbous stemmed flowers are pulled, not cut, from the plant by the grower. This means that the end of the stem is often white and firm. Bulb flowers such as hyacinths, soft stems and should be cut where the green on the stem starts—just above the white bulb, as the stem will often not drink from this white area, therefore, it should be removed completely, as water can only be absorbed through the green part of the stem. Whilst the stems can be cut at an angle, extremely soft stems e.g hyacinths and Daffodils are best cut horizontally. Place the flowers in cold water, since most bulbs bloom when the air and ground are still at low temperatures, they do better in a vase of cold water, unless the flowers are wanted open, as warm water speeds up the development of bulbous flowers. Special flower food for bulb flowers is available, and should be used if possible. 

Special Note – Daffodil stems exude a poisonous sap when cut. This will shorten the life of other flowers if Daffodils are conditioned in the same water. Therefore, they should always be conditioned separately. If they are being arranged in water, they should be arranged separately, but if being arranged in floral foam, this is not necessary, and they can be arranged together with other flowers.


Soft Stems 
Examples Freesia, Hellebore, Anemone.
These should be conditioned by cutting the stem ends at a sharp angle, removing all the lower foliage which will be below the level of the water, and placing the stem ends in a bucket about ha1/4 filled with tepid water, which has had the appropriate amount of cut flower food added. Allow them to have a good overnight drink, the flowers can then be arranged. Hellebores are a special case and benefit from the boiling water treatment – see special notes below for details.

Woody Stems
Examples; Syringia/Lilac, Viburnum opulous/Snowball, Cornus/dogwood, Mimosa, Eucalyptus.

For woody plant material cut the stem at a sharp angle, and split the stem ends by cleanly cutting for about 2 cm. Remove all the lower foliage which will be below the level of the water, and place the stems in a bucket about ¼ filled with tepid water, which has had the appropriate amount of cut flower food added. Be sure to cleanly cut the stems at the ends rather than smash them. This will keep vascular tissues intact and create more surface area to absorb water. 

Semi-Woody Stems 
Examples Chrysanthemum, Lily, Carnation, Asparagus Fern

These should be conditioned by cutting the stem ends at a sharp angle, removing all the lower foliage which will be below the level of the water, and placing the stem ends in a bucket about ¼ filled with tepid water, which has had the appropriate amount of cut flower food added. Special flower food is available for Lilies, and this should be used if possible.


Milky Stems
Examples: Euphorbia, Ficus 
The stems of some flowers exude a milky substance, called latex, when cut. This can be messy, and also can be an irritant if it comes into contact with the skin. 

The sap that oozes into the water and clogs the vascular system of other flowers in the container, preventing them from absorbing water, therefore, plant material in this category should have the stem ends cut, and then stems need to be seared before the flowers are placed in the arrangement. There are two ways to accomplish this: Either dip the cut end of the flower in boiling water for 30 seconds or apply a flame from a match or candle to the per-cut flower stem for a few seconds, to seal it. The cut stem ends can also be rinsed under running warm water to remove excess latex, before placing into warm water for conditioning.

Although in the soft stems section searing is not effective in halting the seepage of secretion from daffodils. Therefore daffodils should not be mixed with other flowers if you want a long-lasting arrangement.

Special Notes for certain types of material:

Carnations and pinks should have their stems cut between the node or joint, as they cannot take up water if cut or broken on the node.

Non commercially grown Hellebores and Hydrangeas are notoriously difficult to condition when very fresh earlier in the season before the ‘weather’. So if picking these from your garden both will benefit from boiling water treatment as follows: Add about an inch of boiling water to a jug, then place the stem ends in the water for around 40 seconds. This will force out the air from the stems and allow better uptake of water. Take them out of the hot water, then re-cut the stem ends and put them into water up to their necks overnight before arranging. A more fool-proof method for Hellebores is to wait until they have formed (or are beginning to form) seed pods. At this stage they will condition very well and last a long time. For Hydrangeas, it is better to wait until they are mature and turning slightly papery before picking as very young flowers often don’t condition well. 

Grey foliage such as Santolina or Senecio, or woolly foliage such as Stachys lanata should never be fully immersed to condition it, as the water is absorbed by the grey covering and the colour of the foliage would be spoiled. Also, absorbed water can be siphoned by these leaves, creating pools of water outside the container.

It’s worth avoiding very new growth, such as spring foliage, as it is very difficult to condition, and does not last well.

One important thing to remember is that stem ends should never be hammered, as this causes damage to the tissues, which leads to a build up of bacteria, and shortens the life of the material. (This used to be a regular practise in the past, however as science and understand has developed it is a technique that is no used or every recommended.)

One of the most common causes of wilting in cut flowers and foliage is the presence of an air-lock in the stem, a bubble of air that becomes trapped and stops the water flow reaching the head of the flower. 

The air-lock usually forms as the flower is cut, when atmospheric pressure forces air into the water ducts of the stem in which there is normally a partial vacuum. Commercial growers use post-harvest cut flower food which ensures air-locks don’t occur. 

Flowers cut from the garden and left for any time before being conditioned will also form an air lock, so always carry a bucket of water with you into the garden, so that you can place the plant material into water immediately, on a temporary basis, thus preventing the stem ends from drying out.