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Gardening Answers Knowledgebase

Plant Answer Line Question

Keywords: Lilium (Lily family), Plants in winter, Bulbs

I was recently given 6 Oriental lily (Lilium) bulbs - bare root. It seems much too cold (late February) to put these in the ground. They are currently naked in the garage, but would it be better to pot them until the ground is workable? I have not raised lilies before, other than daylilies.


Generally, it is good to plant bulbs soon after you get them, but if you need to wait (due to cold weather and unworkable soil), keep the bulbs somewhere cool, and keep them "in moist sand or peat moss until scales plump up and new roots begin to sprout" (Sunset Western Garden Book, edited by Kathleen Norris Brenzel, 2001).

The Gardener's Guide to Growing Lilies by Michael Jefferson-Brown and Harris Howland (Timber Press, 1995) confirms your thought that it is too cold to plant them out in the garden (I would wait until the threat of freezing temperatures subsides). According to the resource mentioned above, Oriental lilies will do very well in pots, so what you could do is pot them now, and if you decide you would like to move them into the garden when it warms up, you could either put them, pot and all, into the border, or gently remove them from the pot without too much root disturbance, and plant them in the soil.

Date 2016-12-30
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Plant Answer Line Question

Keywords: Helleborus, Plants in winter, Pruning

I am noticing that the flower bud shoots for my hellebores (Helleborus x hybridus), are starting to push up above the soil surface. There is still a substantial stand of foliage in good condition.

My question is about pruning. I know I'll need to prune about half the leaves away (I understand that the cut should be made at the base) to give the flowers more visibility. Does it harm the plant to prune it during this cold snap? Does it harm the plant to cut ALL the old leaves off in December as the bud stalks begin to appear?

I would appreciate any guidance you can give me, such as when and how extensively to prune them.


According to Hellebores: a Comprehensive Guide by C. Colston Burrell and Judith Knott Tyler, "all the hybrids maintain their foliage (...) throughout all or part of the winter (...) In any case, as the flower buds begin to stir in the center of the rosettes, it's best to remove all the foliage to make way for the flowers. Nothing spoils the garden display like a tangle of flowers wrestling with winter-burned leaves. The juice is caustic and sometimes causes a rash, so take care when removing the old leaves."

In The Gardener's Guide to Growing Hellebores, Graham Rice and Elizabeth Strangman advise a more time-intensive method:
"The best approach is to cut off some leaves during the autumn and early winter when the garden is put to bed, concentrating on removing dead leaves and any showing signs of blackening (...) By Christmas time they should be thinned out sufficiently to leave a good circle. However, as our winters become windier it may be wise to remove them entirely at this stage. (...)Thin the leaves further as the flower stems emerge, then just before they are in full flower remove all the old leaves. (...) To compensate for the removal of the last of the leaves the plants deserve a good mulch." They go on to suggest compost or a mulch of leaves for this purpose. The cold snap is unlikely to harm even recently pruned hellebores, as they seem to thrive in the cold.

Date 2016-09-24
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Plant Answer Line Question

Keywords: Cold protection of plants, Citrus, Plants in winter

I live in Redmond, WA and I recently noticed that we have been classified as Zone 8A - 8B instead of 7B. Most sources I read state that year-round outdoor planting for Nagami kumquats is recommended only for Zone 8 and above. What is your take on this? I've had a Nagami since November, but it has acted differently from what sources I read indicated. I also have a Meyer Lemon that I bring indoors and it did fine over the winter, but the Nagami shed all its leaves within 2 months starting from January. The peculiar thing was that the leaves shed were all green and healthy, leading me to believe it had entered dormancy. It started to grow new leaves in April, but I'm still puzzled why it entered dormancy in indoor conditions even though the less cold-tolerant Meyer flourished.

Long story short, if the Nagami sheds its leaves every winter, will it ever have enough time to produce mature fruit even if it did survive outside? If you have any particular kumquat or citrus experts you could recommend, that'd be great! Thanks!


According to a local nursery (Raintree), the Nagami kumquat is hardy to 18 degrees, and may produce fruit here. So if we have a cold snap, as we occasionally do, it may be hard on the tree if it's growing outdoors--unless you can provide it with protection. A friend of mine has grown kumquats before, and they produced fruit, but I believe a long period of subfreezing temperature killed her tree one winter/early spring.

Growing Citrus by Martin Page (Timber Press, 2008) says that kumquats (Fortunella japonica or synonymously Citrus japonica) are prone to zinc deficiency which results in smaller leaves and shorter shoots. They are considered very hardy, but this may be "due to their long winter dormancy." Nagami grown in a pot will reach about 4 feet, but outside, it can get to 13 feet tall. Fruit is harvested October to January.

It's possible your Nagami kumquat dropped its leaves because it was entering dormancy, but there are other causes to consider as well. According to the source cited above, leaf drop in citrus trees can be caused by:

  • sudden environmental changes (temperature, humidity, etc.)--bringing a plant inside to overwinter is likely to expose it to dry air
  • underwatering (don't overcompensate by watering a leafless plant because it has no way of transpiring the water without its leaves; prune it the next spring by reducing shoots by about a third of their length)
  • overwatering (make sure container drains well; soil that doesn't drain well can lead to yellowing leaves and leaf drop)

You may want to speak to a local expert at the Western Cascade Fruit Society, or the Home Orchard Society.

Also the nurseries that specialize in fruit trees are good resources:
Cloud Mountain Farm
Burnt Ridge

Date 2016-09-02
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April 11 2017 13:50:16