It's been so nice to be out in the garden. Buds are starting to swell on some shrubs, weeds are growing like gangbusters.  I'm so ready for spring; I just want to clean everything up and plant away.  But this time of year I have to stop myself from doing one particular garden chore.  Some of my plants are looking a little, okay a lot, bedraggled because of frost damage.  I could make them look so much better with just a few snips here and there. 

For example, here is my avocado Persea americana.  I started it from seed. It lives out on my back patio just under a patio cover. On nights I anticipate frost, I cover it with a sheet along with my dwarf citrus that also live on the patio.  It's not looking very happy right about now.  I think most of this is frost damage, but some might also be damage from the weight of the sheet on the little tree.  I'm itching to cut all that brown damage off.  However in Solano County on average, our last frost date is March 15th.  We may get a few more frosts, yet.  Those ugly damaged parts are protecting leaves and stem lower on the plant.  If I cut the damaged parts off now that will just expose more of the plant to any remaining frosts.  So for right now, I just need to... step away... from the pruners.

So, I'm waiting. The holidays have passed, my decorations have been put away, and the Rose Parade has floated into memory. This is usually the time that I begin cleaning up my pruners and preparing to prune my roses. How can I think of pruning when yesterday's high temperature was just shy of 70 degrees?

I enjoy the holidays, and when I'm putting away all the decorations, I've got the idea in the back of my head that I can start to think about spring. By now, we've usually been wearing warm coats all day, watching the rains fall on our sleeping gardens, and spent many days shrouded under thick, dark, grey cloud cover. This season, not so much. Except for a few chilly nights on the town, my warm coats have collected dust in the closet. My kids go outside and play during the day in their t-shirts and flip flops! Can it really be January, when it feels more like October or March outside?

Back to my roses- I have 25 rose bushes in my garden. I love roses, a love passed on to me by my mom, who also loves roses. My ‘Iceberg’ rose (Rosa ‘Iceberg’) falling over in a windstorm is what started me on my path to becoming a Master Gardener. I look at it and my head tells me it is time to prune it, regardless of the beautiful blooms it is still producing. My heart tells me to wait, give it a few more days; maybe we'll plunge in to a real winter soon. In the meantime, I'll go outside and just enjoy the extended display of my beautiful roses.

'Iceberg' rose. (photo by Janet Snyder)

Sitting at Starbuck’s, listening to my friend lament about her overgrown New Zealand Flax (Phormium tenax), a blog idea comes to mind.  She reports being tired of all the brown, dead leaves and just wants to “hack-it”.  Rather than have her take these desperate measures, I thought I could offer some tips to possibly save her flax.  While the best time to prune her flax is late fall after the bloom, a little clean up might be in order.  What works best for me when pruning my flax (Linum flavum: Golden Flax), is a pair of very sharp hand pruners.  Gloves are also a good idea due to the fact that the New Zealand Flax has very tough, fibery leaves, which were at one time used by the Maori people to make clothes.  Begin pruning by cutting off any flower spikes.  Then proceed by removing any dead, browned or damaged foliage as close to the base of the plant as possible.  Depending on the size of your flax, be prepared for a long day of cutting.   It is not an easy task to cut the dead leaves, but you will definitely see the fruits of your labor when new leaves begin to grow back.

Interior view of flax leaves. (photos by Mary Gabbard)

Flax plant.

Is it a frost or a freeze? Honestly, it really does not matter. It is cold! But just in case you are curious, the difference is technical and meteorological.

A freeze (also called an advective freeze) occurs when a mass of cold air brings freezing temperatures into the area. For us, that normally means arctic air coming down from the Gulf of Alaska. It is usually cloudy and windy during a freeze.

A frost (also called a radiation frost) occurs under clear skies with wind less than five miles per hour which allow a temperature inversion to form near the ground where the temperature drops to freezing. Normally the temperature increases with altitude as you leave the ground. An inversion occurs when the temperature above the ground begins to cool at increasing height. If the air is very dry during a frost, no ice forms and it is called a black frost. A white frost forms when the air is holding water that condenses and freezes on surfaces forming ice.

Plants do not care why it is cold and the damage freezing temperatures cause depends on the species and age of the of plant and the amount of  time it is exposed to the cold temperature. Severely frozen citrus may drop off the tree while less affected fruit may look normal but be dried out inside. Tender growth on unprotected flowering plants may turn black once thawed and bamboo (Bambusa spp.) leaves may desiccate and fall off. Other plants such as mondo grass (Ophiopogon japonicus) may be completely undamaged.

If a plant is damaged, the best advice is to wait until spring before pruning out the dead material. Pruning now may lead to further damage from later frosts since damaged branches and leaves may provide some protection. Be patient and let new growth on the plant show you where to prune so you do not cut back too much. The last frost in our area is normally around the third week in March, but Mother Nature can be unpredictable!

For more information on protecting your plants from freezing weather, visit the UC Integrated Pest Management website http://www.ipm.ucdavis.edu/PMG/GARDEN/ENVIRON/frostdamage.html. A search for “frost” on the UC IPM website will also help you find examples of frost damage to many types of plants including fruits and vegetables.

I’ve been walking past  this Pittosporum tobira ‘Variegata’ for at least five years now. It’s in my ‘kitchen’ raised bed, which should have become a vegetable bed, but, lacking enough sun and requiring major soil amendment, became a  place to put plants that I could see from the kitchen. The pittosporum made its way there under false pretences. It’s supposed to produce sweet-smelling white flowers, but its attractive branch structure and variegated leaves are more interesting.

I’ve been pruning it back periodically, because it is really too big for the space, but my husband likes its location (hence the pruning). A few weeks ago, in a vain search for possible flower buds,  I noticed that the new growth had aphids. Not only aphids, but a full complement of ants. It didn’t surprise me, but it means I will have to take some action.

Usually when there are aphids on my roses (which, in Quebec only happens in the spring), I wipe them off or remove them with a blast of water from the hose. If I feel it’s necessary, I’ll use some insecticidal soap solution, but that is rare.  Of course, in California it seems as though it’s always spring, and pruning stimulates new growth. If you prune and fertilize, you’ll get lots of fresh, leggy, sweet-tasting new shoots.

Aphids being tended to by ants. (Photo by Riva Flexer)

So, the ants followed the honeydew trail, and they are "farming" the aphids for their that substance.  They protect aphids from predators, like any good farmer, ants protect a food source, and they eat the aphid excrement. Now I have a dual problem. I’ll let you know what I do to solve it!