Wasn't April glorious? My roses have just been beautiful this year and I am so thankful! I found that they were slow to open this spring, but I moved several of them, so that could be one of  the reasons why. Plus, the weather has been up and down, hot and then cold, sunny and then rain and hail. A mixed bag this spring. 

For me, the dreaded Hoplia beetle population has been lighter this year than in the past. I found that the Hoplia beetles in my yard prefer my pink California native poppies over my roses. Yes, native California poppies come in colors other than orange. Who knew? Since my poppies were very prolific this year, I didn't mind them being on the poppies as opposed to my roses. I also have very few light-colored roses in my yard, and they prefer light-colored ones over dark-colored roses. Those dreaded beetles had been around a couple of weeks before the roses opened, giving them less opportunity to destroy the flowers. They should be gone by the beginning of June for another year. Thank goodness!

Since we are having warmer days and cool nights, it is perfect weather for spider mites. They can quickly destroy a plant in a couple of days, so check the undersides of leaves for them and give them a good hard spray of water to get rid of them. Invite lady beetles into your garden by planting native California plants. Spider mites and aphids are some of lady beetles' favorite foods! 

If you can, try to fertilize your roses before the end of the month. Use organic fertilizers if possible. They will feed your soil as well as your plants. Roses like a constant supply of nutrients including micro-nutrients such as copper, manganese and magnesium in addition to nitrogen (the N on the fertilizer label), phosphate (the P on the fertilizer label), potassium (the K on the fertilizer label), to develop strong blooms and roots. Remember more is not better. Follow instructions on the bag. If you haven't put down a layer of compost, that can be done too.

Make sure you have a good three inches of mulch around the dripline of your roses. It will help to keep weeds at bay, retain water and keep the roots cooler in the upcoming summer weather. 

This month, I have included pictures that show how I have blended California native plants with my roses.  Enjoy!

Until next time … "Do not be impatient with your seemingly slow progress. Do not try to run faster than you presently can. If you are studying, reflecting, and trying, you are making progress whether you are aware of it or not. A traveler walking the road in the darkness of night is still going forward. Someday, some way, everything will break open, like the natural unfolding of a rosebud."  - Vernon Howard

Keep recent plantings well-watered and mulched. Sudden warming plus drying winds can stress plants.

Tasks

• Use a 3-inch layer of mulch around trees and shrubs to retain moisture, suppress weeds and cool soil temperature. Keep mulch several inches back from the base of trees or shrubs to prevent damage to the trunk.
• If oakworms, redhumped caterpillars, or cabbage loopers are present, spray with Bacillus thuringiensis kurstaki (Btk). Repeat every 7 to 10 days for several weeks as a preventative measure.
• Spray aphids with insecticidal soap or blast with a strong spray of water.

Pruning

• Remove suckers on roses and fruit trees.
• Prune and shape camellias, azaleas and hydrangeas after bloom.

Fertilizing

• A little used more often is better than a lot at one time. Follow package directions for specific plants.
• Do not fertilize plants during hot spells.

Planting

• Spring planting season is over. Anything planted this month will need careful watering.
• If you missed planting eggplants, melons or peppers, plant now and keep them moist.
• Propagate geraniums and other soft wood perennials from cuttings.

Enjoy now

• Annuals and perennials: alyssum (Lobularia), maiden grass (Miscanthus), cup flower (Nierembergia), beard tongue (Penstemon), rose, pansy (Viola).
• Bulbs, corms, tubers: tulip, Watsonia.
• Trees, shrubs, vines: snowberry (Symphoricarpos), star jasmine (Trachelospermum).
• Fruits and vegetables: snow peas, squash, strawberries, Valencia orange.

Things to ponder

• Control scale with insecticides or summer horticultural oil. Repeat in June if necessary.
• This season, consider installing drip irrigation to provide for plants without using more water than necessary.

Choices for potting soil mixes have really expanded the last few years. In addition to the standard all-purpose potting soil mixes for acid- or shade-loving plants that have been available for many years local nurseries and especially the big box garden centers, these outlets now stock another dozen or more specialized types of potting soil mixes.

The terms ‘potting soils' and ‘potting mixes' seem to be interchangeable. There is no garden-type soil in these products. They are soil-less mixes of ground redwood or other tree barks, peat moss, composts and/or humus, sand and perlite and/or vermiculite. Vermiculite retains water; perlite improves drainage and aerates the soil to allow roots to spread more easily.

Big box garden centers are the primary sources of gardening supplies and equipment for the majority of home gardeners, especially beginner home gardeners.  It's worth taking a tour of a local big box garden center soils aisle to make note of the choices available and to check labels for specific information on potting soil mix contents and formulations. Master Gardeners' anecdotal information on the results of their use of preferred brands is extremely helpful as well.

The big box home improvement center closest to my home carries several nationally known brands of potting soil mixes, both organic and non-organic, for indoor plants, African violets, cacti and succulents, raised beds and container plants. Types and quality of components and the percentages of those components contained in potting soils vary widely by manufacturers; labels often provide minimal information.    

Some labels on both organic and non-organic potting mixes claim that their potting soils will feed plants for 6 or 8 months, and that less watering is required. The tiny list on the very bottom of the bag (reading glasses required) provides percentages of the additional fertilizer added to the soil. There may also be mention of an added wetting agent, but the wetting agent is not always named. Wetting agents or surfactants, both synthetic and organic (e.g. yucca), help keep potting soils from drying out and help water move through the soil. 

The percentages listed of added nutrients in almost all of the products is very low, 0.10 percent on average. A good quality low-nitrogen organic fertilizer will contain at least 4 percent nitrogen. The minute amounts of added chemically derived fertilizers can be easily leached out with watering. Organic potting soil mixes that contain natural ingredients like bat guano, earthworm castings or dehydrated manure may continue to provide lower-percentage nutrients for a longer period of time, but plants potted in either type of mix will require additional applications of a good quality fertilizer on a consistent basis to ensure vigorous growth and health throughout their growing seasons or lives. 

Most perennial potted plants benefit from annual repotting and soil replacement since potting soil mixes often quickly lose their capacity to retain water and nutrients during our long, hot summers, with or without an added wetting agent.  The time span between waterings depends mostly on the quality and composition of ingredients and the density and texture of the potting soil.   

Whether the pest you face is plant or animal, remember safety first. Read labels thoroughly before opening containers that hold garden chemicals.

Tasks

• Check drip and sprinkler systems – clean filters, check emitters, fix leaks and re?set timers.
• Watch for Western grapeleaf skeletonizer. Use Bacillus thuringiensis (Bt) to control.
• Control gophers and moles with traps, baits, or fumigation.
• Clean up drying vegetation within 30 feet of structures for fire prevention.

Pruning

• Remove spent lilac flower clusters just above points where leaf buds are forming.
• Hedges grow vigorously this month. Trim lightly every 2 or 3 weeks to maintain size and shape. Heavy pruning exposes the interior to sunburn.
• Thin apples to one fruit per cluster.

Fertilizing

• A little used more often is better than a lot at one time.
• Fertilize almond, apple, cherry and plum.
• Fertilize citrus.

Planting

• Spring planting season is over. Anything planted now will need careful watering.
• Fruits and vegetables: cucumber, eggplant, okra, parsley.

Enjoy now

• Annuals and perennials: California poppy (Eschscholzia), blue marguerite, coral bells (Heuchera), iris, sweet pea (Lathyrus), Texas ranger (Leucophyllum).
• Bulbs, corms, tubers: harlequin flower (Sparaxis tricolor).
• Trees, shrubs, vines: cistus (rock rose), rose.
• Fruits and vegetables: butter lettuce, peas, spinach.

Things to ponder

• This is the month to propagate geraniums and other soft wood perennials from cuttings.