Question of the week — How far back do I prune my knock out roses and the salvia greggi for the winter? Also, the plant behind my pond I believe is a papyrus plant…. do I need to trim that back too? how about my grasses-should I cut them now?
Here is the best answer that I can give Angie and all of you– about waiting to trim before Valentine’s Day or after each year–
I know that the weather is nice–BUT— It is best to wait until after Valentines day to prune–the reason is –you can have warm weather ( usually comes and goes in Jan – Feb- like now ) that can stimulate excessive new growth when you trim before Valentines Day- Especially if that weather is between 50 degrees or warmer and stays around for a while—-then –almost always you will have freezing weather later ( usually in Late Feb- March) that will burn that new growth right off–If the periods of unseasonal warmth put on a lot of new growth because you trimmed ( trimming doubles the effort of the plant to grow and bloom)–it sets your bloom and growth cycle back that spring– quite a bit.
I want to be sure that you understand–Warm weather itself can cause early growth and bloom-but there is nothing you can do about that –and that won’t put on as much new growth as it would – if you trim before Feb 14th as well. This is true of all hardy perennial evergreens 9 palnts that do not lose leaves in winter)and deciduous plants ( plants that lose their leaves in winter but still have the branches and stems to leaf out on next year) like the salvia greggii and the all season roses. Most of the time this will not kill these plants and roses-it just sets them back–better to wait until after Feb 14th.
If you cut your Cyperus and Grasses now it can cause them to have their new growth damaged or distorted- if that new growth is up very high and uncovered because the old growth was cut off. They are both herbaceous plants ( plants that are perennial – but come back from the roots-and we cut the dead tops off each spring to stimulate new fresh growth). If you have herbaceous plants that are hardy this usually will not kill them- just cause some damage.
When you trim hardy perennials after Feb 14th–there is not enough time for the cycle that I have warned about in the above sentences to occur-( at least it hasn’t happened in my lifetime)-Once our late winter does come in – ( usually mid Feb-early March) it tends to have short cycles of high and low temperatures off and on for a few days at a time – or stay chilly for a long time ( which does not stimulate any new growth)-then we have spring weather in April–and things start to grow and really bloom with out danger of a freeze. By May we are usually already complaining about the heat.
Some of the plants in your garden are tender perennials– like the Mexican Bush Sage –A tender perennial is a plant that usually comes back here but sometimes our winters are too cold-depending on where it is planted ( tender perennials should be sheltered from the north ) and we can lose them. Since removing the the tops takes away protection of any young starts that can shoot up – if you get a real cold late freeze and new growth has been pushed up because of a warm winter early on–it could kill them–(Even if you start seeing green growth come up under the old growth–don’t cut the tops off–you can remove the old growth later -just above the new growth and the new growth will continue to grow and cover what you had to leave. Tender perennials are best left uncut until mid March unless they are very protected or unless you are willing to run out and cover them in case of a late hard freeze .
While it has not happened much in my lifetime–it is not unheard of that we have no winter at all–I do remember a few that we could say that about -but only a few– and since we never really know what our ever changing weather in the DFW area will do –-My advise is to wait until after Feb 14th to start cutting back your gardens. (if you have jumped the gun and trimmed already–don’t fret– you may have to do some extra trimming off of burned growth–but it will all be straightened out by May)
Now however is a great time to make plans and get activities that could hold you inside later when it is time to really get out there and start spring projects all finished up ( Feb14th- March 31) .