Green and mature seed pods of Arroyo Lupine (Lupinus succulentus)

It’s time to start collecting a variety of spring wildflower seeds.  Many annuals already have seed pods that are literally popping!  These pods dehisce, or split, along their length forcefully expelling the seed away from the plant.  For pods such as these, collect the stems when a few of the pods begin to open, and allow the remainder of the pods to mature and dry in a paper bag.  You could also remove individual pods from the plant as they are turning from green to the ripened tan color, just before they split and disperse the seed.  Plants to keep an eye on are the gold poppies (Eschscholzia californica and E. californica ssp. mexicana) and lupines (Lupinus sparsiflorus and L. succulentus).  Other annuals such as bluebells (Phacelia campanularia) also have seed maturing, but they don’t have the dispersal mechanisms like the above mentioned.  It is still a good idea to collect the ripe seed from them fairly soon if you intend to store it in order to prevent insects from eating it.  After seed is harvested, the dying annuals can be cut or pulled from your garden and added to your compost pile.

Trixis (Trixis californica) seed heads

Many perennials and shrubs are also offering mature seed at this time.  Penstemon stems are loaded with seed that can now be scattered in your garden for later germination or stored for planting in the fall.  Brittlebush (Encelia farinosa) and Trixis (Trixis californica) have ripened seed that can be gathered, cleaned of debris, and stored in a cool, dry, dark location.

As we are moving into the hot season, practice smart watering strategies.  It is best to water as infrequently as possible but deep enough to encourage full, vigorous root development.  This is what keeps plants healthy through the summer.  Overwatering creates super-lush foliage that attracts sucking and chewing insects.  Underwatering stresses plants and can cause other pest and disease problems.

As temperatures rise through the month, some vegetables or herbs may need some shade protection.  Mulching the soil surface with compost can create a buffer to keep the soil cooler and more moist, and root systems less stressed.

Ironwood (Olneya tesota) blooms

The beautiful Ironwood trees (Olneya tesota) will be blooming this month.  Don’t be alarmed if you notice your tree’s foliage yellowing and dropping as the flowers begin to open.  This is just its normal cycle.  New foliage will develop and be full once the seed pods develop following the bloom.

Snout weevil larvae

If you didn’t already apply a systemic pesticide to protect your vulnerable agaves from the dreaded snout weevil in April, do so quickly.  Marathon (the chemical Imidacloprid) has proven effective in deterring the adults from laying eggs when agaves are about to bloom.  Agaves will absorb the chemical from the soil, and this will kill any larvae that might begin eating the base of the plant.  Agave murpheyi, A. parryi, A. weberi, and the different forms of A. americana seem to be most favored by these evil agave destroyers.

Gulf fritillary larva on Passion Vine (Passiflora caerulea)

If you have Passion Vines (Passiflora spp.) in your garden, you may have already noticed munching on the foliage.  The exquisite gulf fritillary butterfly lays its eggs on the Passion Vines for the caterpillars to develop.  If they are devouring too much of the foliage on your vine, you can pick some of them off and toss them where they will be conspicuous to the birds.  Avoid using the pesticide Bacillus thuringiensis (sold as Dipel, etc.), as this may kill all of the caterpillars on your vine, and you won’t get to enjoy the beautiful adults in your garden.

Texas Mountain-laurel (Sophora secundiflora) webworm larvae

You probably will want to use the Bt (Bacillus thuringiensis) on your Texas Mountain-laurel (Sophora secundiflora), however, if it is plagued with the less desirable genista webworms.  The powder is effective on the caterpillars, but there are usually more than one cycle of these moths through the season, so you may have to apply it again if they reappear.

Palo Verde webworm

This is the time of year when you might see another type of webworm in your Palo Verde tree (Parkinsonia spp.).  The caterpillars of this moth will eat some of the foliage, but they typically don’t cause too much harm.  They complete their life cycle and are gone for the season.

Cochineal scale on cholla (Cylindropuntia sp.)

Remember to hose off your Prickly-pear (Opuntia spp.) and Cholla (Cylindropuntia spp.) cactus periodically if you get infestations of the cochineal scale.  This will keep populations of the insect low enough to prevent damage.

Gardening Calendar Archive

November 2007
October 2007
September 2007
February 2008

Garden Meetings:

Arizona Native Plant Society
Tuesdays / 7-9 p.m. / September 9, October 14, November 11, and December 9
Webster Auditorium
Call Doug Green at 480-998-5638 for more information.

Central Arizona Cactus & Succulent Society
Sundays / May 18, June 29, July 27, and August 24 / 2 p.m. / Dorrance Hall
Call Judy Braun-Brody at 480-481-8129 for more information.

Central Arizona Butterfly Association
Saturday / May 10 / Boyce Thompson Arboretum

Maricopa Audubon Society
Tuesdays / 7:30-9:30 p.m. / September 2 and October 7 / Dorrance Hall
Call Laurie Nessel at 480-968-5614 for more information.