Fa-la, 'tis May, the merry month of May! That naughty month where everyone goes blissfully astray!"

Sorry; we couldn't help bursting into song, because with the onset of May, Northern New Mexico gardeners are reassured that spring is finally here at last.

May's the month for final winter garden cleanup, purchasing necessary hardscaping, repairing and replacing tools, preparing plant beds and containers, starting seeds, hardening off plants you've been growing indoors for outside use, and — particularly after May 10, the last official frost date for the Santa Fe area — planting, planting, planting!

There are lots of happy activities vying for our attention this month, so let's dive right in ...

MAY CLEAN-UP 

Remove litter from garden beds. Bag and trash any weeds left over from last season (don't put them in the compost heap or you'll have weed seeds coming up everywhere). Dig up and compost the sad remains of last year's annuals.

• Scrub out with hot soapy water all your empty metal or plastic planters, pots, trays, and windowboxes. Rinse well, then allow them to air-dry completely before reusing.
• Wash tools free of dirt and plant parts. Sharpen dull tools (or have them professionally sharpened). When time comes to use your pruning tools, have a container of alcohol or other disinfectant ready to drip their blades into between cuts. This will help prevent the spread of disease from plant to plant.
• Remove the old potting soil and rootball-remnants from your outdoor annual and vegetable containers. Replace with fresh planting mix: we recommend Happy Grower™ Raised Bed and Container Organic Growing Medium; Ball Professional Growers' Mix™ (No. 2 is fine-textured, No. 3 is coarser and better drained) ; or Ferti-Lome Ultimate Potting Mix™.
• Check your soaker hoses and drip lines for damage and repair or replace them. Plastic and rubber exposed to our high ultraviolet sunlight tend to break down quickly, developing little holes that spray you in the face when you turn on the water. To prevent such degrading, bury your driplines under at least 4 inches of mulch: we recommend Payne's Soil 100% Natural Soil Conditiner, Jolly Gardener Cypress Mulch™; Nature's Way Composted Mulch™; or Soil Mender Cedar Mulch™.
• Clean out your water barrels and replace any damaged spigots or sleeves.

MAY COMPOSTING
Nobody ever has enough compost. For complete instructions on building and maintaining your home compost heap, click here.

MAY SOIL PREPARATION
New Beds: Double-digging is the best way to prepare a planting bed on a site that's never been dug before (or hasn't been dug over for a long time). It will seem at first like a lot of work, but the results will repay your efforts a hundredfold, whether you plan to grow annuals, perennials, herbs, vegetables, shrubs, trees, or a row of windsock geese and pink plastic flamingoes. For detailed double-digging instructions, including recommendations for soil amendments, click here.

WHAT TO PLANT IN MAY
Trees, shrubs, vines, hardy grasses, and hardy perennials may all be planted this month.
• Click here for "How To Plant A Tree or Shrub" in Northern New Mexico.
• For a list of favorite trees for Northern New Mexico, click here.
• Click here for a list of favorite shrubs suited to our area.
• For a list of favorite perennials for Northern New Mexico, click here.
• Click here for a list of favorite ornamental grasses suited to our area.

Santa Fe's traditional "frost-free" day is May 15. Although weather forecasts are showing above freeing temperatures, we recommend you resist planting annuals until at least May 10th unless you’re prepared to cover them well at night or take them inside come evening. Tomatoes, peppers, eggplants, and everything in the squash and melon families need very warm soil, so store-bought plants should not be set outdoors in Santa Fe until June 1st unless you have ways of insulating them from cold snaps. If you live in Pecos, Glorieta, Taos, and similar cool spring areas, be alert to late frosts, and to the chilling effects of wind on your newly planted vegetable starts. If in doubt, cover the plants at night with plastic flower pots, then remove the pots in the morning. It may seem like a lot of bother, but it can save you the heartbreak of STWS (Sudden Tomato Wilt Syndrome)!

Seeds To Plant In May Outdoors
Flowers:
• bachelor's buttons (Centaurea cyanus)
• calendulas
• calliopsis (Coreopsis tinctoria)
• cosmos
• daturas
• four o'clocks
• hollyhocks; will bloom next year
• love-in-a-mist (Nigella), great for clay soils
• marigolds
• morning glories (soak seeds overnight in warm water before planting)
• nasturtiums (soak seeds overnight before planting)
• Shirley poppies (Papaver rhoeas)
• sunflowers
• tithonias (Mexican sunflowers, Tithonia rotundifolia)
• zinnias (late May onwards; direct-seeded zinnias will catch up quickly to transplants)

Herbs & Vegetables:
• basil (late May onwards; sow the seed on the soil surface and don't cover it up — it needs
light to germinate)
• chives
• cilantro (ASAP)
• dill (ASAP)
• garlic chives (also called "Chinese chives")
• onions (sets)

Bulbs & Roots To Plant In May Outdoors
• crocosmias & montbretias
• dahlias (late May onwards)
• gladioli (late May onwards)
• lilies
• onion sets
• potatoes

Seeds To Plant In May Indoors
Indoors, you may still start the seeds of all the above, as well as:
• eggplants
• moon vine
• painted tongue (Salpiglossis)
• peppers, sweet or hot
• petunias
• salvias
• snapdragons
• sweet marjoram (the fresh leaves and flowering tops make one of the most delicious teas when sweetened with honey)
• tomatoes (it's not too late for the short-season varieties)

What Not To Plant Yet: If you live in Santa Fe, you might want to consider waiting until June 1st to plant outdoors the seeds of the following:
• calabacitas
• corn
• cucumbers
• melons
• pumpkins
• string & shelling beans
• soybeans
• summer & winter squash

If you absolutely can’t stand waiting another minute, you can start seeds of the foregoing indoors in peat pots and full sun beginning about May 15th, but these same seeds sown outdoors after June 1st will by the end of June have caught up with the ones you planted earlier indoors.

MAY PRUNING
General rule of thumb #1: Don’t overprune. The more you cut from a plant, the more stressed you make it, and stress means the plant will have a weaker constitution more vulnerable to insect pests and disease.

General rule of thumb #2: use clean, sharp tools, and dip their cutting parts in undiluted household vinegar (a natural disinfectant) between each cut (see “Tools” above). 


Specific Pruning Tasks For May
• Cut off at soil level the aboveground parts of herbaceous perennials (perennials that die down completely to the ground in the winter).
• Cut back native grasses that are two years old or older.
• Prune out any dead, weak, wounded, or crossed branches of shrubs and trees.
• Paint tree pruning-wounds with wound sealant to prevent the ingress of pests and diseases.
• Lightly prune to shape your rose of Sharon (Hibiscus syriacus); for larger blossoms, cut back the previous year’s bloomed-out wood to two buds per branchlet
• Prune your roses by removing any dead canes, or weak spindly canes that are rubbing against larger ones. Roses that bloom only once, in spring or early summer (like ‘Austrian Copper’ and most old roses), may also have their spent blossoms pruned later in spring just after flowering, unless you wish the hips for autumn and winter show: cut back the old flower-stems to the first pair of 5-part leaves. Recurrent-blooming roses, that bloom off and on all summer, may be pruned similarly between bloom-flushes.

What Not To Prune Yet: Don’t prune your forsythias, spring-blooming fountain butterfly bushes (Buddleja alternifolia), or lilacs until they’ve completed their spring flowering. After they finish flowering, cut back your fountain butterfly bushes to ground level, or, if this prospect makes you feel too much like a murderer, at least halfway (50%); for forsythias take out a third of the just-flowered branches and any dead or diseased wood; remove the spent blossom-clusters of your lilacs just to the next lower set of leaves.


WHAT TO DIVIDE IN MAY

Dividing perennial clumping plants helps keep them vigorous. Most summer-blooming hardy perennials, such as yarrow (Achillea), Jupiter’s beard (Centranthus ruber), and hummingbird mint (Agastache), can be divided at this time, before they have developed too far.

• Have your new planting hole ready before you take your divisions.

• Make sure you cut through the rootball cleanly, with a sharp spade, as far down as you can, so that you lose as few roots as possible.

• Plant the division immediately (the longer you wait, the more likely it will suffer from transplant shock) in soil that has been enriched with compost, well-aged manure, and/or a slow-release plant food.

• To guard against transplant shock, water in your transplant with a solution of 1 teaspoon per gallon Super-Thrive® or Green Light™ Root Stimulator; repeat the following week.

• Keep the transplant well-watered until it has had a chance to establish a good root system. This means watering it three times a week for the next couple of months.


WHAT TO FERTILIZE IN MAY

Using appropriate plant foods, and following all label directions, feed everything in sight this month: trees, shrubs, vines, perennials, hardy herbs, lawns — you name it. For established beds, sprinkle your fertilizers around the plants and scratch the soil amendments into the top 3 inches of the bed. Mulch and water thoroughly. For new beds, see “May Soil Preparation” above.

Well-composted horse, sheep, cow, or llama poop makes great fertilizer, but make sure it’s thoroughly aged; i.e., not stinky or slimy any more. Otherwise, it could burn your plant-roots.

Other popular organic fertilizers include Michael Melendez’s Soil Secrets® line of soil amendments; Yum-Yum Mix™, which is made in the Southwest for Southwest soils; the Peace of Mind™ line of organics; and Bradford Organics™. Alaska™ fish emulsion, a liquid plant food, is also popular; but if you have dogs, watch out — it is the preferred cologne of huskies and retrievers everywhere.

Inorganic fertilizers, such as the Bayer™ line, Miracle-Gro™, Osmocote™ time-release, or Jack’s Classic™ (our equally effective and now much less expensive substitute for Peter’s™ fertilizers), can also be very useful. These fertilizers are particularly handy when you’re growing plants in containers, such as tubs and hanging baskets, where plant roots are restricted from traveling far afield in search of lunch. Indoors, these fertilizers don’t attract fungus gnats the way many organic fertilizers can. Just be sure to flush out your indoor potted plants with pure water once a month to prevent the buildup of excess fertilizer salts in the pots (visible as a white film on the soil or pot surfaces).

If you employ inorganic fertilizers in outdoor garden soils, remember that such fertilizers, used over time, can raise chemical salt-levels in the soil to the point where the salts can damage beneficial microbes that plants need to digest their food. So in order to feed those microbes the fertilizer-salts might be diminishing, be sure to add to the earth around your outdoor plants plenty of organic compost, such as our TTP Supreme Compost™, and Michael Melendrez's wonderful Earth Magic™ and Protein Crumblies™ soil health renewal products.

More On Fertilizers
Fertilizers come in different forms, all of which are most effective when applied directly to the root zones of your plants. Water-soluble fertilizers must be mixed with water each time you fertilize, but they are readily available to your plants. Granulated time-release fertilizers such as Osmocote™ can last up to three or four months in your soil, releasing nutrients to your plants every time you water.

Plant spikes are time-release fertilizers shaped into pointed cylinders. To use them, make holes at intervals along the dripline of the plant you wish to feed. Make the holes deep enough to reach the plant’s root zone. Insert a plant spike into each hole, and water thoroughly. The spikes will dissolve slowly over time, feeding your plant as they do.

Foliar Feeding
Foliar feeding is the practice of feeding plants through their leaf pores. These pores, called "stomata," can absorb nutrients readily if the nutrients are applied in liquid form in the cool of the day (preferably before 9:00 A.M. Mountain Time). You may begin foliar feeding of plants as soon as plants begin to leaf out and continue it throughout the growing season.

Remember that foliar feeding is not a substitute for in-ground fertilizing, but a useful adjunct to it. Popular organic foliar foods include Neptune's Harvest™ liquid seaweed (a natural growth stimulant and plant-strengthener rather than a fertilizer as such) and Alaska™ fish emulsion. Among the many inorganic foliars available are Miracle-Gro™; Jack’s Classic™; and Carl Pool’s B-61™, a powerful high-phosphorus flower fertilizer popular with annual and bedding plant growers.

For more information on fertilizers and their applications, click here.

MAY PEST & DISEASE CONTROL

Weed Seed Inhibitors: If you haven’t already, apply corn gluten meal to lawn areas to inhibit the sprouting of weed seeds. If you have broad-leaved weeds in your lawn already, and if hand weeding seems too onerous to you, apply herbicides to them, but do so on a day relatively free from wind, or you might poison your ornamentals, too.

Dandelions: Before they have a chance to flower or set and distribute their seeds, dig up invading clumps of dandelions (get those roots!). Assuming they haven’t been treated with herbicide, put some of the young leaves in your spring salads.

Sun-Scald: To prevent the trunks of your newly planted trees from being scalded by the sunshine on exposed sites, paint the trunks with a dilute solution of 1 part water-based interior white latex paint (cheapest grade works just fine!) mixed with 4 or 5 parts water.

Little Critters: Be on the alert for aphids sucking the juices of your tender young plant-shoots and buds, and for cutworms, which look like little hairless caterpillars and curl around tender young plant-stems at ground level, chewing through them like tiny buzz saws.

Aphids can be killed with Safer's™ Insecticidal Soap, neem oil, or ordinary dish detergent diluted to a ratio of 1 tablespoon per gallon of water. Apply every 3-4 days to catch successive generations of hatchlings. Cutworms can be foiled by encircling the soft stems of young plants with collars cut out of plastic, metal, or cardboard (toilet roll cylinders work great). Be sure the collar extends at least 2 inches below and at least 2 inches above the soil line for best results.

Birds, too, can be a nuisance this time of year, as any farmer knows: they often eat newly sown seeds, and some species will nip young shoots of vegetable transplants and certain annuals (I had house sparrows devastate some newly-planted hanging basket carnations).

Scarecrows and flapping flags will scare off some avians, and translucent, spun-fiber row covers will keep them (and most insect pests) off young vegetable plantings.

Setting out bird feeders will give them something else to nosh on. Don't forget to provide wild birds with a source of water. That's often what they're seeking when they nibble on tender new foliage or flower buds. Your bird water dish or bath should be no more than 2 inches deep so that smaller birds can't drown in it.

Pocket Gophers and Rabbits

Pocket gophers are rodents that burrow underneath your garden and feed off your plants' roots, often pulling the entire plant (we kid you not) under the soil for leisurely later consumption.

Rabbits and hares do a lot of garden damage, too; some have been known to climb into window-boxes to feed. Rabbits and hares are not technically rodents, but lagomorphs, critters who digest their food by first eating it, then allowing it to pass through their digestive tracks to emerge as poop, then gobbling up said poop to complete the digestive process.

There are various ways of dealing with pocket gophers and rabbits. You can try killing these garden predators by:
• placing traps or poison gas canisters in their burrows (warning: follow label directions precisely and keep pets out of the garden)
• getting a cat or dog and setting it loose in your garden
You can try dealing with these critters nonviolently by:
• setting out Hav-A-Heart™ traps which imprison your bunnies and gophers harmlessly for relocation (warning: they often find their way back).
• digging a trench near the garden and every day set out vegetable scraps for them (several customers have reported this effective in cutting down rabbit depredation)
• surrounding your plants — or your entire garden — with frames of chicken wire to keep aboveground rabbits from getting to the foliage (make sure to sink the wire at least 6 inches into the soil to discourage them from burrowing under it)
• digging planting holes, lining them with fine-mesh wire, then setting your plants in those holes (the wire will help keep the burrowing pocket gophers from doing the Invaders From Mars bit on your dahlias)
• growing your treasures in large planters and half-barrels.

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