Starting a Garden
If you have an interest in gardening, you are not alone. Gardening is one of the fastest growing hobbies in 2020. People garden for a variety of reasons – saving money (a $4 tomato plant can produce 10 to 20 pounds of yummy tomatoes), fresher, better tasting vegetables, ensuring that produce is organic, stress relief, and great exercise.
Starting a garden is exciting! Planting a tiny seed in the warm earth, watching as the new plant emerges and grows, then picking that first tomato or zucchini connects us to nature as nothing else can. Nothing beats the taste of garden fresh vegetables and the satisfaction of having grown them yourself. Unfortunately, weeds, poor soil, destructive insects, rodents, uncooperative weather, and over or under watering can quickly destroy a garden and dishearten a gardener. You can avoid many of these problems and enjoy gardening more if you dig into the following tips!
Start With a Plan
Starting a garden is a bit like building a house. First, you need a plan. Plants need sunlight, water, the proper balance of nutrients, the right temperature range, and someplace to put their roots. Before you buy your first package of seeds or fledgling plant, ask yourself these questions:
Where can I start a garden? If you have a large backyard, you have far more flexibility than someone with only a corner next to the pool. Apartment and condominium dwellers may only have a patio or balcony for gardening. If space is limited, grow up, not out by trellising vine crops. No matter where you live, a garden, no matter how small, is possible with a bit of creativity!
Keep in mind that most plants need some direct sunlight. However, during the summer the Arizona sun is too intense for many of the vegetables gardeners would like to grow, so shade structures may be needed. If you have an HOA, check the rules! You may need to keep any structures below the top of your fence and front yard gardens are probably not allowed.
Your garden will need a source of water, so proximity to a faucet may be important. How you choose to water your plants will depend on how large a garden you have, how much time you want to spend watering, and the resources available. Hand watering with a watering can or hose works well for a few plants. For larger undertakings, you can install drip systems, use soaker hoses, or continue to water with a hose. As I add more growing beds, fruit trees, grapes, and cane fruits I will install drip systems controlled by timers. For now, hand watering suffices.
If you plan to use bottomless raised beds or plant directly in the ground, you will need to remove any Bermuda grass. There are several methods of dealing with the tenacious turf. Chemical warfare using glyphosate is one method. Glyphosate has been linked to several types of cancer including non-Hodgkin’s lymphoma and it is not selective as to which plants it kills. Depending on the formulation and concentration of the product, the waiting period for planting food plants after using glyphosate is three days to never. Although I have resorted to glyphosate on occasion, I do not use it in areas where I plan to grow food.
Another method is to cook it by solarizing with clear plastic. The method is simple, but not quick. First, cut the grass as short as possible. Water deeply, soaking the soil to a depth of two feet. This step is counterintuitive, but the moisture is necessary. Cover the area plus two feet on each side with UV resistant clear plastic. If more than one sheet of plastic is needed to cover the area, overlap the sheets by six inches. Secure the edges with soil, bricks, boards, logs, rocks, or whatever you have handy that will keep it in place.
This is best started in March or April when Bermuda grass wakes from its winter dormancy. Leave the plastic in place through the summer. You should see condensation on the underside of the plastic. If the soil dries out to the point that you no longer see condensation, you can briefly pull the plastic aside and water the area. The idea is to stimulate growth while increasing temperature to lethal levels. Some gardeners prefer using black plastic in the same way, but research favors clear plastic. A simple example of the difference between clear and black plastic is when a car is parked in a sunny area in July. As we all have experienced, the interior gets hot. Really hot! If the windows are tinted, less sunlight passes to the interior and the car stays cooler. Solarizing may or may not kill all your Bermuda grass. Most of the roots will be in the top six inches of soil, but they can penetrate to a depth of six feet! Any roots that survive will grow.
Depriving Bermuda grass of sunlight is another popular method of killing it. If you have tried to grow a Bermuda grass lawn, you may have noticed that it did poorly in heavily shaded areas. As with solarization, start in March or April. First, use a mower or weed eater to cut the grass as short as possible and remove the cuttings. Soak the ground to a depth of two feet. Add a layer of heavy cardboard such as flattened moving boxes or appliance boxes. Stores such as Lowe’s will give you appliance boxes, but be prepared to be there when the appliances are delivered. Overlap the cardboard edges by about six inches so the grass cannot sneak through. Secure the cardboard with sod staples or tent stakes. Wet the cardboard layer until it is saturated. Spread a two- to three-inch layer of compost over the cardboard. Finally, add a thick (at least 2 to 3 inch) layer of wood chips. Keep the area damp for six to eight weeks. The water will encourage the grass to grow. Growth takes energy which is usually replenished by photosynthesis. Without sunlight, the grass exhausts its stored energy and dies. You can then rake the wood chips aside and plant in the compost. The cardboard will have broken down by this point and plant roots will easily penetrate it. A cover crop such as clover, cowpeas, or buckwheat is a good soil-building step in this process. The cover crop is dug into the soil before the garden is planted.
Because Bermuda grass is so hard to kill, you will need to be vigilant and dig out any surviving bits as they sprout. At the first sign of growth, water the area deeply and dig out the roots. Try to get the entire root as even one small piece can quickly sprout into a whole new crop!
What would I like to grow? It makes no sense to plant okra for a summer crop if your entire family hates okra! If your family cannot get enough of fresh green beans, plan to extend the harvest with succession planting. If you want to have tomatoes as well as some to can or dry, you should plant varieties suitable for those purposes. Beefsteaks are great on sandwiches, but do not can or dry well!
What grows well in my area? My planting, harvesting, and seed starting calendars assume you are in USDA zone 9b. If you are not sure of your zone, check the USDA zone map. Most vegetables and many fruits and berries can be grown here if you select the right varieties and create the right microclimate.
Future posts will highlight desert-hardy varieties of fruits and vegetables. Buying from local nurseries with knowledgeable staff is a good start. When ordering seeds or plants from catalogs, check the growing zones listed. A great resource for open-pollinated, native seeds is Native Seed Search. If your neighbors are gardeners, strike up a conversation and ask what grows well for them. Microclimates can and do exist within USDA zones! Besides, gardeners love to talk about their gardens.
How good (or bad) is my soil? Whether you plan to garden in the ground as I do, or in raised beds or containers, you need to be on a first-name basis with your soil! I strongly recommend having your soil tested by a lab.
I routinely test my soil with a home test kit for quick reference, but it only tests for pH, nitrogen (N), phosphorus (P), and potassium (K). The pH is a measure of how acidic or basic (alkaline) your soil is with 7 being neutral. The higher the number, the more alkaline the soil. Most plants do best with a soil pH of 5.5 to 6.5, the pH at which nutrients in the soil are most available to the plants. Soil structure is also affected by pH. You can read more in-depth information on pH here. Nitrogen, phosphorus, and potassium (N-P-K) are the nutrients listed on fertilizer bags. It is also important to know how much calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), and various trace minerals are in your soil, which the lab test will include. In addition, the home test kit only measures total N, while the lab test breaks it out as nitrate and ammonium. A good lab test will also include recommendations for amending your soil.
As I develop my urban homestead, most of my garden plots will be in the ground. The method I use is a modified version of the double digging method developed by John Jeavons and elements from regenerative agriculture and no-till gardening. To compensate for the deficiencies of our native soil, I use far more compost than Jeavons recommends and I do use a rototiller to break up the ground initially. The use of the rototiller is necessary (in my opinion) to deal with my rocky, clay soil. Since I need to sift out the rocks, disturbance is unavoidable. Once the initial work is done, I can move to no-till methods. As I start new garden plots, I will post the details.
If you plan to garden in containers or raised beds, you will most likely need to purchase good quality planting mix. Planting mix is not mulch or compost. It is a mixture of sand, silt, clay, and broken-down organic matter, called humus. There are several options for obtaining planting mix for container and raised bed gardening.
Buy bags of planting mix (not potting soil!) at a garden center or nursery. While convenient, this can be an expensive option if you need a large quantity. I suggest reading the label carefully and checking online reviews before purchasing because quality can vary greatly. I cannot personally recommend any brand of planting mix, but I will be testing several and will post my results. One brand I believe is worth trying is Tank’s Green Stuff. The company is in Tucson and sells both bagged and bulk planting mix. You can purchase their bagged product through retailers such as Ace Hardware and Summer Winds Nursery.
Buy planting mix in bulk. There are several local companies that make planting mix and sell it in bulk for pick up or delivery. Once again, I recommend that you do your research before purchasing your planting mix. Some Arizona companies that offer bulk planting mix are Tank’s Green Stuff, Singh Farms, and Pioneer Landscaping. If you have recommendations, please leave a comment!
Make your own! The companies mentioned above as well as garden supply stores and nurseries are sources for the ingredients. Another Phoenix business that carries what supplies is the Arizona Worm Farm. A good recipe for planting mix is:
1 part finished compost
1 part peat moss or coconut coir
1 part vermiculite
The “parts” are by volume, not weight! So, a five-gallon bucket of each component would make fifteen gallons of mix. Make sure to wet the ingredients thoroughly as you mix them. The finished compost provides nutrients; peat moss or coconut coir prevents compaction and holds moisture; and vermiculite holds nutrients, prevents compaction, and holds moisture. Peat moss is slightly acidic with a pH of about 4.4. Coconut coir has a neutral pH of about 7. For a detailed discussion of the pros and cons of each, click here.
Over time, you will notice the level of the mix in your beds or containers drop. This is because the compost continues to decompose into finer pieces. The vermiculite and peat moss or coconut coir do not break down. Just add more compost as the level drops.
Another recipe for planting mix is:
50% topsoil
30% finished compost
10% peat moss or coconut coir
10% vermiculite
The percentages are by weight NOT volume. Keep in mind that topsoil is not the native soil we have in most of the desert. As in the previous recipe, mix all the ingredients well and wet thoroughly. Mix while adding water until the planting mix is as damp as a wrung-out sponge. Fill your planting beds, add a drip system if desired, and start planting! Add more compost as the soil level drops over time (usually once a year).
There are many other planting mix recipes just a Google search away. Everyone who does container or raised bed gardening has a favorite. If you have a “go-to” recipe, feel free to post it in the comments.
Wherever you plant your garden, raised beds, containers, or in the ground, make sure there is good drainage. Raised beds with bottoms and containers need drainage holes. A layer of gravel in the bottom keeps the drainage holes from clogging.
If your garden is in the ground, you can check drainage by performing an infiltration test. Dig a hole at least 12” deep and 12” in diameter. (It is a good idea to dig several holes unless your planting area is quite small.) Keep the sides straight. Measure the depth of the hole. Fill the hole with water. After 24 hours, refill the hole with water. Check the water level frequently until all the water disappears. Find the average infiltration rate by dividing by dividing the total depth of the water (12”) by number of hours (or fractions of an hour) it took for all the water to disappear.
For example, if it took five hours for 12” of water to infiltrate, 12” divided by 5 hours is 2.4 inches per hour. That is the average infiltration rate.
A good infiltration rate is about 2” per hour. Most garden plants will grow well with an infiltration rate from 1” to 3” per hour. Less than 1” per hour generally indicates a compacted and/or clay soil. Poor infiltration can also occur if a layer of rock lies under the soil. An infiltration rate greater than 4” per hour means that soil is very sandy and will not hold enough water to support garden plants. If your soil drains too slowly or too quickly, adding compost will help build soil structure correct drainage issues. If infiltration is very poor, you may need to break through an underlying layer of caliche, a type of dense, hard clay. If this is not feasible, choose a location with better drainage or build raised beds.
It is also important to know the composition of your soil. Soil is made of sand ( particle size 2.00 to 0.05 mm ), silt (particle size <0.002 mm), and clay (particle size < 0.0002 mm) plus organic matter. Particle size affects how quickly water passes through soil and how well nutrients are retained. Sandy soil drains quickly and does not hold nutrients well. Clay soils, which are often rich in nutrients needed by plants, are sticky when wet, do not drain well, and are hard when dry. The mineral portion of good garden soil, known as loam, is about 40% sand, 40% silt, and 20% clay by weight. Loam retains nutrients, yet it drains well. If your soil is not an ideal loam, adding organic matter can compensate.
You can perform a simple test to determine the composition of your soil.
Jar Test for Soil Texture
Materials:
Jar with straight sides
Permanent marker
Timer (watch, stopwatch, phone)
Ruler
Dish detergent
Sieve or colander (one you do not mind getting dirty)
Procedure:
1. Collect the soil. Sift out any rocks and larger pieces of organic material (leaves, sticks, etc.)
2. Fill the jar 1/3 full of the sifted soil.
3. Add water to about 1” from the top of the jar.
4. Add dishwashing detergent (1 teaspoon for a pint jar; 2 teaspoons for a quart jar)
5. Put the lid on the jar and shake it briskly until the soil is thoroughly mixed with the water.
6. Set the jar on a level surface and start timer for one minute.
7. After one minute, use the marker to mark the level of the sand layer that will have settled at the bottom of the jar.
8. Leave the jar undisturbed for two hours, then mark the level of the silt layer that will have settled on top of the sand layer.
9. Leave the jar undisturbed for 48 hours. Mark the clay layer that will have settled on the silt layer. Any organic matter will be floating at the top.Use the ruler to measure the total height of the soil and each soil layer. Calculate the percentage of sand, silt, and clay by dividing the height of each layer by the total height of the soil. Use the soil triangle diagram to determine your soil type.
Example: Total height of soil = 5 inches; height of sand layer = 2 inches; height of silt layer = 2 inches; height of sand layer = 1 inch
(2 ÷ 5) x 100% = 40% sand
(2 ÷ 5) x 100% = 40% silt
(1 ÷ 5) x 100% = 20% clay
Find 40 on the bottom leg of the triangle for the sand component; 40 on the right leg of the triangle for the silt component; and 20 on the left leg of the triangle for the clay component. Find the point in the triangle where the three lines meet. This example would be a loam soil.
Are there critters (mice, rats, rabbits, ground squirrels, dogs, cats, chickens, children, etc.) that could destroy my garden? Few things are more frustrating and disappointing than having your garden eaten, trampled, or excavated by critters! From local wildlife snacking on plants and almost-ready-to-harvest vegetables to domestic animals and children digging up or trampling plants, critters can quickly wreak havoc in a garden.
A sturdy fence around a garden can save your garden and your sanity. Poultry netting makes an inexpensive and effective barrier for most critters, although mice easily slip through. For problems with mice, the old-fashioned snap trap is highly effective. Just remember to keep them away from pets and children. If mice steal the bait without tripping the trap, try putting crunchy peanut butter under, not on top of the trigger. If you are plagued with gophers, you can dig down and place a subterranean barrier of poultry netting under and around your garden. Placing poultry netting under open-bottomed raised beds works well for gopher control. A less labor-intensive method of gopher control is gopher traps. The traps are set in their tunnels.
What about “bugs” that eat my plants? When it comes to insect pests, the old saying, “an ounce of prevention is worth a pound of cure” is the best approach. Companion planting can deter many pests. Some plants are offensive to the “bad bugs” and some disguise the scent of target plants making it harder for the pest to find them. There are many good publications that deal with companion planting. You can also refer to my companion planting table.
Keeping plants healthy is also important in avoiding insect pests. Stressed, weak plants are more likely to be attacked. Proper watering, neither too much nor too little, soil rich in organic material, planting for the season, shade as needed, and mulch all help plants stay healthy.
Invite beneficial insects into your garden by planting herbs and flowers to provide nectar and shelter for adults of species such as parasitic wasps and hover flies. They will reward you by laying their eggs on the larva of pests where their voracious offspring will devour the pest before it devours your plants. You can purchase praying mantis egg cases and lady bugs, who will also appreciate having plenty of plants for cover. Praying mantis will eat any insect they encounter. Lady bugs and their larva consume huge numbers of aphids.
Now that you have the basics, start making your garden dreams a reality! You can start your gardening adventure any time of the year here in the desert southwest. Just follow this guide and get growing!
