March in the Low Desert

Spring is in the air, or is it?  It still is possible to have freezing temperatures early in the month, so don’t store your frost protection cloth yet.  By mid-March chances of below, freezing temperatures have diminished for the low-desert regions and spring gardening tasks can now be initiated.

Now is a good time to divide clump-forming Agave spp., Aloe spp., Manfreda spp., Hesperaloe spp., and Candelilla (Euphorbia antisyphilitica) in the landscape or in containers.

Many deciduous trees will start to produce new leaves as the weather becomes warmer including Mesquites (Prosopis spp.), Desert willow (Chilopsis linearis), Golden Leadball Tree (Leucaena retusa), Feather Tree (Lysiloma watsonii), and Kidneywood (Eysenhardtia orthocarpa).

Stem and flower buds are forming on many cacti at this time.  Look for these buds on Prickly-pears (Opuntia spp.), Chollas (Cylindropuntia spp.) and Hedgehogs (Echinocereus spp.).

Plant your Ocotillo (Fouquieria splendens) from March through May as these are the ideal months to achieve greater transplanting success.

November through mid-March is the ideal time to plant the Joshua Tree (Yucca brevifolia).  If unable to plant by mid-March, wait until November for increased chance of survival.  If planted during the summer months, they are more sensitive during the transplant process either from the ground or a container.  They will exhibit more signs of stress and dehydration as well as more prone to rot if over watered.

If rainfall was plentiful during the previous fall-winter months, look for colorful wildflower displays in the desert.

•    Mexican Gold Poppy (Eschscholzia californica ssp. a )
•    California Poppy (Eschscholzia californica ssp. californica)
•    Desert Bluebell (Phacelia campanularia)
•    Scorpion-weeds (Phacelia spp.)
•    Chia (Salvia columbariae)
•    Bladderpod (Lesquerella gordonii)
•    Lupines (Lupinus spp.)
•    Owl-clover (Castilleja exserta)
•    Baby Blue Eyes (Nemophila menziesii)
•    Monkey Flower (Mimulus guttatus)
•    Desert Stork’s Bill (Erodium texanum)
•    Emory’s Rock Daisy (Perityle emoryi)
•    Fiddlenecks (Amsinckia spp.)
•    Parry’s Penstemon (Penstemon parryi)
•    Firecracker Penstemon (Penstemon eatonii)
•    Superb Penstemon (Penstemon superbus)
•    Brittlebush (Encelia farinosa)
•    Evening Primrose (Oenothera caespitosa)
•    Black-foot Daisy (Melampodium leucanthum)
•    Paperflower (Psilostrope cooperi)
•    Desert Verbena (Glandularia gooddingii)
•    Desert-marigold (Baileya multiradiata)
•    Deer Vetch (Lotus rigidus)
•    Fendler’s Bladderpod (Lesquerella fendleri)
•    Wishbone Bush (Mirabilis laevis)
•    Globemallow (Sphaeralcea ambigua)
•    Angelita Daisy (Tetraneuris acaulis)
•    Gopher Plant (Euphorbia rigida)
•    Scarlet Sage (Salvia coccinea)
•    Fleabane (Erigeron divergens)
•    Blue Dicks (Dichelostemma capitatum)
•    Bush Morning Glory (Convolvulus cneorum)
•    Desert Zinnia (Zinnia acerosa)
•    Creosote (Larrea tridentata)
•    Bee Brush (Aloysia gratissima)
•    Desert-honeysuckle (Anisacanthus thurberi)
•    Baja Fairy Duster (Calliandra californica)
•    Pink Fairy Duster (Calliandra eriophylla)
•    Chuparosa (Justicia californica)
•    Ocotillo (Fouquieria splendens)
•    Mexican-honeysuckle (Justicia spicigera)
•    Giant Bur-sage (Ambrosia ambrosioides)
•    Bur-sage (Ambrosia deltoidea)
•    Red Barberry (Mahonia haematocarpa)
•    Woolly Butterfly Bush (Buddleja marrubiifolia)
•    Bitter Condalia (Condalia globosa)
•    Texas Mountain-laurel (Calia secundiflora syn. Sophora secundiflora)
•    Bush Dalea (Dalea pulchra)
•    Tree Ocotillo (Fouquieria macdougalii)
•    Desert-lavender (Hyptis emoryi)
•    Ragged Rockflower (Crossosoma bigelovii)
•    Bush Germander (Teucrium fruticans)
•    Wolfberries/Thorn berries (Lycium spp.)
•    Little-leaf Sumac (Rhus microphylla)
•    Sugar Bush (Rhus ovata)
•    Autumn Sage (Salvia greggii)
•    Desert Sage (Salvia dorrii)
•    Hopbush (Dodonaea viscosa)
•    Paperbag Bush (Salazaria mexicana)
•    Feathery Senna (Senna artemisioides)
•    Parish’s Goldeneye (Viguiera parishii)
•    Trixis (Trixis californica)
•    Sweet Acacia (Vachellia farnesiana syn. Acacia farnesiana)
•    Palo Blanco (Mariosousa willardiana syn. Acacia willardiana)
•    Blue Palo Verde (Parkinsonia florida)
•    Little-leaf Palo Verde (Parkinsonia microphylla)
•    Palo Brea (Parkinsonia praecox)
•    Mexican-ebony (Havardia mexicana)
•    El Chañar (Geoffroea decorticans)
•    Baby Bonnets (Coursetia glandulosa)
•    Blackbrush Acacia (Vachellia rigidula syn. Acacia rigidula)
•    Shoestring Acacia (Acacia stenophylla)
•    Beavertail Cactus (Opuntia basilaris)
•    Silver Cholla (Cylindropuntia echinocarpa)
•    Mother of Hundreds (Mammillaria compressa)
•    Mammillaria senilis
•    Viznaga Caballona (Ferocactus macrodiscus)
•    Mohave Yucca (Yucca schidigera)
•    Joshua Tree (Yucca brevifolia)
•    Don Quixote’s Lace (Yucca treculeana)
•    Slipper Plant (Pedilanthus macrocarpus)
•    Live Forevers (Dudleya spp.)
•    Crown of Thorns (Euphorbia milii)
•    Yellow Trailing Iceplant (Malephora lutea)
•    Coppery Ice Plant (Malephora crocea)
•    Ice plants (Drosanthemum spp.)
•    Kalanchoe orgyalis
•    Succulent Geraniums (Pelargonium spp.)
•    Aloes including Aloe x ‘Blue Elf’, Partridge-Breast Aloe (Aloe variegata), and Coral Aloe (Aloe striata)

Look for flowering Claret-cup (Echinocereus continues), Engelmann’s Hedgehog (Echinocereus engelmannii) and Green Hedgehog (Echinocereus viridiflorus) later in the mon



As temperatures rise during the month of March, turn on your irrigation timer.  Test the timer to see if it is working properly and replace back-up batteries if necessary. Check for leaks and clogged emitters and flush out the poly lines.

How much to water depends on many factors including: soil type, weather, rainfall, microclimates, cultural practices, plant size and species, and whether the plants is newly planted or established in the landscape (two years or more). Below are general guidelines to help you determine how much and how often to water your landscape and container plantings to keep them healthy when rainfall is lacking.

Established native or desert-adapted trees and shrubs should be watered at least once to twice monthly. Water at least three feet deep for your trees and two feet deep for your shrubs.

Natural rainfall may be adequate for most well-established cacti and succulents. However, if rainfall is insufficient, water may be needed at least once to twice during the month of March. Water your cacti and succulents to a depth of at least 8-12 inches.

Established herbaceous perennials, groundcovers, and vines should be watered every two to three weeks and at least one foot deep.

Wait a week after planting your cacti and succulents before watering to minimize the chance of rot. After the initial irrigation of your succulents, allow the soil to dry out and water every 10-14 days. Cacti may need to be watered once more after initial watering during the month of March, but allow the soil to dry out between watering.

Newly planted desert-adapted trees and shrubs need to be watered more frequently until established.  It can take up to 3-5 years for trees and at least 1-2 years for shrubs to become established in the landscape. After planting your trees and shrubs, they should be watered immediately and for the next few days to keep the root ball from drying out. Schedule your irrigation cycle for trees and shrubs every 7-10 days during the month of March. Allow the soil to dry out between irrigations and always water deeply, three feet for trees and two feet for shrubs.

Newly planted desert-adapted herbaceous perennials, groundcovers and vines should be watered immediately and for the next few days to keep the root ball from drying out. Schedule your irrigation cycle for herbaceous perennials, groundcovers and vines for at least once to twice weekly and to a depth of one foot. Allow soil to dry out between watering.

Continue to water your annual wildflowers at least every two weeks to prolong flowering.

Agaves and other succulents (Aloe spp., Dudleya spp., Cotyledon spp., Pedilanthus macrocarpus, Euphorbia spp.) in containers should be watered at least once to twice this month. Cacti in containers should be watered at least once this month. However, cacti and succulents in small containers may need to be watered more often including cacti and succulent seedlings.

Keep an eye on your warm-season annuals and herbaceous perennials in containers. Water them at least once to twice weekly.


Plant warm-season cacti and succulents including:
•    Saguaro (Carnegiea gigantea)
•    Prickly-pears (Opuntia spp.)
•    Barrel Cacti (Ferocactus spp.)
•    Hedgehogs (Echinocereus spp.)
•    Pincushions (Mammillaria spp.)
•    Agaves (Agave spp.)
•    Yuccas (Yucca spp.)
•    Candelilla (Euphorbia antisyphilitica)
•    Desert Spoon (Dasylirion wheeleri)
•    Red-yucca (Hesperaloe parviflora)
•    Giant Hesperaloe (Hesperaloe funifera)
•    Elephant Food (Portulacaria afra)
•    Slipper Plant (Pedilanthus macrocarpus)
•    native Limberbushes (Jatropha spp.)

When transplanting cacti and succulents, mark either the south or west side and plant facing the orientation you marked to avoid the burning of tender tissues. Most nurseries will mark the side of the container to help you determine proper planting orientation. However, if the original orientation is not known, newly planted cacti and succulents need to be covered with shade cloth if plant surface appears to yellow or pale suddenly. Use a shade cloth rated between 30-60%, anything higher will block most of the sunlight and will not be suitable for your cacti and succulents. You may need to keep the shade cloth on the plant for the duration of the summer.

Plant native and desert-adapted trees including: 
•    Ironwood (Olneya tesota)
•    Blue Palo Verde (Parkinsonia florida)
•     Little-leaf Palo Verde (Parkinsonia microphylla)
•    Mesquites (Prosopis spp.)
•    Golden Leadball Tree (Leucaena retusa)
•    Chihuahuan-orchid Tree (Bauhinia lunarioides)
•    Texas-olive (Cordia boissieri)
•    Desert-willow (Chilopsis linearis)
•    Baby Bonnets (Coursetia glandulosa)

Plant warm-season shrubs including: 
•    Yellow Bells (Tecoma spp.)
•    Desert Cotton (Gossypium thurberi)
•    Sennas (Senna spp.)
•    Velvet-pod Mimosa (Mimosa dysocarpa)
•    Fire Bush (Hamelia patens)
•    Ruellia (Ruellia peninsularis)
•    Mexican Bush Sage (Salvia leucantha)
•    Sky Flower (Duranta erecta)
•    Bird of Paradise species (Caesalpinia spp.)

Plant warm-season herbaceous perennials including:
•    Datura (Datura wrightii)
•    Desert Four O’Clocks (Mirabilis multiflora)
•    Wine Cups (Callirhoe involucrata)
•    Arizona Foldwing (Dicliptera resupinata)
•    Gaura (Gaura lindheimeri)
•    Hummingbird Trumpet (Epilobium canum ssp. latifolium)
•    Plumbago (Plumbago scandens)

Many vines can also be planted at this time including: 
•    Queen’s Wreath (Antigonon leptopus)
•    Yuca (Merremia aurea)
•    Passion Flowers (Passiflora spp.)
•    Slender Janusia (Janusia gracilis)
•    Arizona Canyon Grape (Vitis arizonica)

When planting desert-adapted plants it is usually unnecessary to back-fill with soil amendments and vitamins or to add rooting hormones. However, a slow-release fertilizer high in nitrogen and phosphorous can be added to the back-fill, if necessary.

Many cacti can be started from seed at this time. Seed can be soaked overnight in water to help start the germination process.  Place seed in a well-draining soil mix (½ quality potting soil and ½ perlite or pumice) and lightly cover. Keep soil moist until germination occurs.

Sow seed of warm-season annuals and herbaceous perennials including:
•    Mexican Hat (Ratibida columnifera)
•    Red Sage (Salvia coccinea)
•    Mexican Chia (Salvia hispanica)
•    Tarahumara Chia (Salvia tiliaefolia)
•    Sunflower (Helianthus annuus)
•    Numerous cultivars
•    Hollyhock (Alcea rosea)
•    Summer Chia (Hyptis suaveolens)
•    Chocolate Flower (Berlandiera lyrata)
•    Tickseeds (Coreopsis spp.)
•    Golden Crownbeard (Verbesina encelioides)

Warm-season vegetable seeds started indoors in January can now be transplanted to your garden. Vegetables to transplant include:
•    Globe and Jerusalem artichokes
•    Eggplant
•    Peppers
•    Tomatoes
•    Tomatillos
•    Sweet potato slips

Try the many varieties of chiles such as Del arbol, Chiletepin, Mirasol, and Tabasco.

Vegetable seeds to sow include:
•    Beets (early half of the month)
•    Carrots
•    Sweet corn
•    Flour corn
•    Popcorn
•    Cucumbers
•    Jicama
•    Cantaloupe
•    Watermelon
•    Tomatillos
•    Muskmelon
•    Green onions
•    Pumpkins
•    Radishes
•    Summer squash
•    Winter squash
•    Gourds
•    Sunflowers
•    Black-eyed peas

By mid-month plant amaranth, Lima bean, snap bean, okra, and peanut. Try the many types of native beans such as Chihuahua Canario, O’odham Pink, Tohono O’odham Vayo Amarillo, and Yoeme Purple String from Native Seeds/SEARCH.

•    Anise
•    Basil
•    Catnip
•    Chives
•    Epazote
•    Fennel
•    Feverfew
•    Horehound
•    Hyssop
•    Lemon balm
•    Salad cress
•    Parsley
•    Safflower
•    Salad burnet
•    Santolina
•    Fenugreek
•    Winter & summer savory
•    Thyme
•    Yarrow
•    Sesame



•    Basil
•    Bay
•    Cuban-oregano
•    Lemon grass
•    Lemon verbena
•    Mexican-oregano
•    Chives
•    Curry
•    Feverfew
•    French tarragon
•    Garlic chives
•    Germander
•    Horehound
•    Lavender
•    Lemon balm
•    Marjoram
•    Mint
•    Oregano
•    Parsley
•    Rue
•    Sage
•    Santolina
•    Winter & summer savory
•    Scented geraniums
•    Tansy
•    Thyme
•    Yarrow




Pruning should be done to maintain plant health (remove dead, damaged or diseased portions, cross branching, etc.), to highlight the “natural” shape of the plant, to train a young plant, and to eliminate hazards.  Excessive or heavy pruning causes significant stress to trees and shrubs.  The best practices are to prune the least amount necessary and prune for legitimate reasons.  How much to prune depends on the size, species, age, as well as your intentions.  A few good principles to remember–a tree or shrub can recover from several small pruning wounds faster than from a single large wound and never remove more than 25% of the canopy in a year.  For more information register for a Garden class offered on pruning that will teach you the proper pruning techniques for trees and shrubs or visit for information on proper pruning of young and mature trees.

By mid-month frost damaged plants can be safely pruned. Prune evergreen trees and shrubs.

Pruning newly planted trees and shrubs is not recommended and in fact can be detrimental. However, corrective pruning off broken or torn branches and/or limbs can be done at planting time. Save other pruning activities for the second or third year. For more information on developing a healthy tree visit

Now is a good time to prune summer and fall flowering shrubs including:
•    Texas Sages (Leucophyllum spp.)
•    Yellow Bells (Tecoma stans)
•    Lantana (Lantana camara)
•    Turpentine Bush (Ericameria laricifolia)
•    Black Dalea (Dalea frutescens)
•    Mexican-honeysuckle (Justicia spicigera)
•    Sky Flower (Duranta erecta)

Wait to prune your prickly-pears (Opuntia spp.) and chollas (Cylindropuntia spp.) until after flowering. Spent stalks of aloes, agaves and other succulents can be removed at this time.

Warm-season herbaceous perennials, groundcovers and vines can be pruned at this time including:
•    Chocolate Flower (Berlandiera lyrata)
•    Plumbago (Plumbago scandens)
•    Mexican Hat (Ratibida columnifera)
•    Gaura (Gaura lindheimeri)
•    Mealy-cup Sage (Salvia farinacea)
•    Rock Verbena (Glandularia pulchella)
•    Trailing Lantana (Lantana montevidensis)
•    Dyssodia (Thymophylla pentachaeta)
•    Queen’s Wreath (Antigonon leptopus)
•    Passion Vines (Passiflora spp.)
•    Yellow Orchid-vine (Callaeum macropterum)

Prune by cutting back to emerging growth or to the basal rosette (group of leaves arranged from a central point).

Continue to deadhead annuals and herbaceous perennials to encourage continued flowering including Desert Marigold (Baileya multiradiata), Red Sage (Salvia coccinea), Angelita-daisy (Tetraneuris acaulis), and Gaillardia (Gaillardia pulchella).


Most native and desert-adapted plants in the landscape do not generally require fertilizer as they are adapted to our soil conditions. In most cases, fertilizers are generally applied to prevent deficiencies. If fertilizers are needed, one application for the year is usually sufficient.

Now is the time to fertilize your warm-season cacti, succulents, herbaceous and woody perennials, and annuals in containers. Periodic fertilization may be needed for plants in containers as nutrients will have diminished in the soil over time. Depending on the type of fertilizer used, follow directions on the label.

Continue to fertilize your vegetable and herb garden as needed.  March is also a good time to apply a layer of composted mulch to your vegetable and herb beds.


Aphids can be found on landscape plants or on your vegetables. Allow natural predators such as lacewings, praying mantis, lady beetles and even hummingbirds to control the aphid population. You can also spray with insecticidal soap, but check to make sure beneficial insects are not presently working.

If you notice a tattered appearance on your landscape plants such as Evening Primroses (Oenothera spp.), Sacred Datura (Datura wrightii) and Gaura (Gaura lindheimeri) it may be the flea beetle in action. A different species of flea beetle may also harm your vegetables including tomatoes, eggplants, carrots, and cabbages. The flea beetle larvae and adults can be destructive and they can be difficult to control.

You may notice small, circular cuts on the leaf margins at this time. This is the handiwork of leaf-cutter bees, important pollinators. The leaf-cutter bees use the cut leaf to line their nest and then lay an egg in each cavity. The damage is cosmetic and does not harm the plant. Control methods are unnecessary.

Look for mealybugs on your cacti and succulents. These scale insects can be difficult to control due to their ability to reproduce rapidly and they quickly acquire resistance to chemical controls. Spray mealybugs with a 70% alcohol-water solution.

Fine webbing between leaves or stippling on leaves may indicate the presence of spider mites. These plant mites cause damage by sucking contents from the leaves and are difficult to detect due to their small size. Plants that are water stressed may become susceptible to infestation. Dusty conditions can also lead to spider mite outbreaks. Make sure your plants are well-watered and wash off accumulated dust on plants to manage spider mite problems. You can also remove by using a fast spray of water or by spraying insecticidal soap to control populations. There are many biological controls that feed on spider mites including lacewings, predatory mites and big-eyed bugs. Using pesticides is not recommended as pesticides do not help manage the population, but can actually cause the population to intensify.

Cochineal scale, the cottony, white substance on your prickly-pears (Opuntia spp.) and chollas (Cylindropunita spp.) may be active now. Remove by using a fast stream of water or spray insecticidal soap.

Agave snout weevils become active during the warm months and infestation may not be apparent until it is too late.

Psyllids may be active during the month of March. Psyllids are sap feeders and many are plant specific or feed on a closely related group of plants. High populations of psyllids can cause distortion and die back of new growth, and in some cases defoliation. To keep populations under control do not overwater or over fertilize your plants as this causes excessive growth.  Yellow sticky traps can also be used to control the adult population.

A white, frothy substance may be visible on plant stems. This is caused by spittle bugs. Manage by spraying stem off with a strong jet of water to remove infestation. Spittle bugs generally do not cause much damage to plants.

Weeds that germinated with the fall-winter rains will begin to flower at this time. You can manually remove by hand. To manage weeds in larger areas, spray with glyphosate following directions on the label. Adding a small amount of marker dye in the glyphosate solution can be helpful to avoid spraying the same areas twice. When using a chemical spray use an old pair of shoes that will never be worn indoors.  The glyphosate product can be used around cacti and most succulents without damaging them.  It is also inactive in the soil, so it will not harm the roots of other plants.

You may notice rabbits eating new, tender growth on your plants or flowers. It may be necessary to cage plants temporarily, or spray Liquid Fence TM to help deter these animals.