By Russell Haughey
While walking the hills of Arizona looking for javelina, deer or birds, I’m sure many of us have noticed a plant that impressed us with its especially pretty flowers, foliage or fruit. Have you ever thought about growing one of your favorite native plants from seed you collected in the wild? Many of our native plants make great landscape or potted plants. Often these plants attract wildlife with their flowers or fruit, or because they provide cover. With a little effort, you can enjoy the satisfaction of planting a plant that you raised from seed you collected yourself. This article will give you the basic knowledge to grow a plant from seed.
My yard is planted with many living souvenirs of my trips throughout the southwest and Mexico. Some of my favorites include an interesting relative of the ocotillo that I grew from seed I collected near Hermosillo Mexico. The saguaros, organ pipes, senitas and cardons growing in my yard were all grown from seed I brought back from various trips. I also have an elephant tree grown from seed collected in the Tinajas Altas near Yuma. I even have a greythorn that I grew from seed that I found in the crop of a dove from my Master’s thesis research. Many times the seed I plant does not come up, but the plants that do have been with me for years. Nothing ventured, nothing gained.
Many attractive native Arizona plants are hard to find in nurseries. Often this is not because the plant won’t make it in a residential landscape, but because nurseries don’t think there is a market for that particular plant. Growing natives from seed is a good way to get unique plants for your landscape that will be around for years to remind you of those great trips you took around the southwest.
The first step is to find a stand of plants to collect seed from. If you happen to find your plant in the wild in fruit with ripe seed, you are in luck. Sometimes plants will begin to have ripe fruit or seed while the flowers are still flowering. But often we notice a plant because of its showy flowers, and its seed may not be ripe yet. In that case, or if there is just a particular plant that you want, go to the library or the internet and look up the plant and find out when the plant flowers or sets fruit, and where it can be found. Or, talk to an expert at the Boyce Thompson Southwestern Arboretum or the Desert Botanical Garden, or email me at firstname.lastname@example.org. Then schedule a trip to a place where the plant grows during the fruiting season to collect seed.
Generally, each species of plant will set flowers and produce seed when it is most advantageous for that particular species. Basically, winter annuals will set seed in late spring and summer annuals tend to set seed in August or September. Most desert trees or shrubs set seed in May, June, or July. Most cactus fruit; like saguaros, organ pipes, night blooming cereus, or senitas, are usually ripe in mid summer.
If you make a trip into the field and find that your timing is a little off and your seed is not ripe yet, or has already dispersed, don’t despair. Look around the area. Often plants of a particular species flower and fruit later higher in elevation, or on a north or east facing slope; and flower and fruit earlier on a south or western facing slope, or at a lower elevation. Also, there may be seed lying on the ground around the plant hidden between rocks or in the leaf litter. Or, you may find seed in coyote scat in the area. One of my saguaros is from seed I found in coyote scat. So, feel free to pick through there and bring home whatever you want to plant, but I wouldn’t eat it!
Because plants have such different fruits and seeds it takes all sorts of methods to collect and prepare seeds; many of which you will have to invent. So, I will give you some basics, and you can use you ingenuity from there. First, you should collect the seed when it is ripe. Most seed will be ripe when it is dry, hard, and when the fruit or pod is opening up. Saguaro seeds are ripe when they turn back inside the fruit, even before the fruit turns red and splits open. Palo verde seed is ripe when dry and hard.
Many plants, especially wildflowers, have flower stalks that will be in all stages at the same time; flowering, fruiting, and dispersing seed. With these plants you can pick the flower stalk, turn in upside down in a paper bag, and let it dry out. As it dries some fruits will ripen, these along with the already ripe fruits will drop their seed to the bottom of the bag for easy collection. Paper bags are great for storing and transporting seed and fruit. They will allow the fruit or seed to dry out, whereas plastic bags will retain any moisture and cause mildewing of the fruit.
Seeds of many plants such as cactus, berries and others will have to be manually separated from the fruits. Sometimes the dried fruit can be crushed, and the seed can be separated from the chaff by winnowing. With fruits such as saguaro fruit, the inside pulp can be scooped out, mashed up, and dumped in water. The good seed will sometimes tend to sink to the bottom of your bucket, and the pulp will tend to float. Then you can pour off the water along with the pulp, leaving behind most of the seed in the bottom of the bucket. Always make sure to dry the seed out as soon as possible to avoid premature germination or mildewing.
Basically, three times of year are best for germinating different kinds of plants. These guidelines apply mainly to southern Arizona. Winter annuals have evolved to take advantage of our winter rainy season and do best when planted in November or December. Summer annuals and our more tropical perennials such as cactus germinate best during the summer, especially in August. These plants have evolved to take advantage of our summer rainy season. Many other plants germinate best when their seed is planted in spring; March through May. These guidelines are very general, and it is often hard to predict when one of the 3,800 or so species of plants found in Arizona germinates best. So if you don’t have any success with your seed in April, you may want to try again in August, or October.
In general, seed will germinate if given adequate moisture, oxygen and temperature. Commercial garden seeds are bred to ensure a high percent germination without any special treatment. But many wild seeds have special dormancy requirement to ensure that the seed will germinate at a time and under conditions that will give them a better long-term chance for survival. Some wild seed will germinate without any special treatment; others will require some special treatment. Many seeds are viable for about a year and the percentage of seed that will germinate will decrease every year thereafter. Some seed needs to go through a cold moist period (some people call this “winter”). This strategy ensures that the seedling does not germinate until after the winter, when springtime conditions are followed by a long summer for the first year’s growth, after which the plant will be better able to survive the winter. Artificially providing these special temperature and moisture conditions is called “stratification”. For example, nurserymen will prepare many cold climate seeds (maples, oaks, and perhaps walnuts) for germination by putting them in moist peat moss or sawdust in a sealed tub in the refrigerator for about 6 weeks. The seed is fooled into thinking it has been though the winter and it is now springtime and time to germinate. Plant the seed in a warm moist pot and it will now germinate.
Many seeds germinate better if they are “scarified”, especially desert bean trees like mesquite, acacias and other desert trees and shrubs. No, this does not mean that you have to sneak up and frighten the seed. This would probably traumatize them so much they would never germinate. Plants are very sensitive, you know. It means the seed coat must be nicked through to the endosperm (white center) to allow the seed to take on water when planted more readily than if you did not nick the seed. In nature, this thick seed coat ensures that the seed does not germinate until there is enough moisture from a big enough storm event to ensure that the developing seedling will have enough soil moisture to continue growth until the next rain. Scarifying the seed cheats the system and gives a higher percentage of germination for the budding hunter/naturalist/horticulturist.
Many of us have seen mesquite seedlings germinating out of a moist cow pie. Chewing and the digestive action of the cow has scratched and moistened these seeds. The seeds are then passed out into a moist pile of organic mulch (cow pie), which gives the young seedlings a favorable microsite for their initial development. To artificially scarify the seed, scratch a nick in the seed coat with a knife or file. Scratch until you see the color of the seed coat give way to the lighter color of the inside of the seed. Sometimes soaking the seed overnight will help the seed take on water. Pouring boiling water over the seed will sometimes work. Commercial nurserymen soak seeds in acid to eat away the seed coat, but for small quantities of hard coated seed, I prefer to use a file.
Seed of annual wildflowers should be broadcast and lightly raked over, to cover the seed and to hide it from birds. Keep the ground moist with a light, deep sprinkling until the seed begins to germinate. If conditions are right, germination should take 5-10 days. After germination, water deeply only as often as needed to prevent the plants from wilting. Thin and weed as necessary, or as much as you have time or patience for. Winter annuals planted in late October will flower in March; summer annuals planted in June or July will flower in August or September.
Usually I like to start perennial plants in small pots, about 4 inches in diameter. I will separate the seedlings later when they get crowded. When they hardened off and large enough I may plant them into the ground, or maintain them in pots until they are bigger.
Another method is to germinate the seed in a food storage container. Put the seed between a few layers of moistened paper towel in a sealed tub and check them every day until you see a root emerging from the seed. Then carefully remove the seed and place it in soil and keep it moist as it continues to germinate and grow. If the seeds fail to germinate after a few weeks, or become moldy, either they are too old, or there is some other dormancy mechanism that needs to be overcome.
To start perennial seeds in pots, plant the seed about 1/2 inch apart and in a mix of about 1/3 commercial compost, 1/3 loam, and about 1/3 sand, vermiculite or perlite. There are many good soil mixes, but make sure it drains well enough that water will not stand on the surface more than 30 seconds but that the soil retains moisture for a day or two. I sprinkle a top dressing of pea-sized gravel in a thin layer over the surface of the soil. This helps keep the soil moist, and provides the little microsites that seeds like for germination. It also helps keep the seed from bouncing around when you water.
Label the pots so you can remember when you planted what. Water with a fine mist often enough to keep the soil moist until the seed germinates, then only often enough to keep the seedlings from wilting. Germination should take 5-10 days if conditions are right. When you water, always water deeply. Water until the water starts to drip out of the bottom holes. This prevents an accumulation of the salts that are present in our water. Water or soil that is too salty will prevent germination.
It is important to provide the proper amount of light. Too much sun will dry out the pots too soon for germination and shrivel up the tender seedlings if they do germinate. Too little sunlight will grow weak, leggy plants that will sunburn when you move them to the ground. Indoors is too dark. Under a porch is probably too dark. Under a fully leafed out mulberry tree is too dark. Filtered sunlight works best; sunlight that is partially (50 %) shaded by lattice, shade cloth or the scattered branches of a palo verde tree.
Young seedlings are vulnerable to pests, especially birds and rodents. Thrashers and cactus wrens seem to get a lot of satisfaction out of scattering my seedlings and labels all over the place. Although I grow these plants for wildlife, I would like them to benefit animals for longer than a week. So, I started to cover my seedlings with bird netting. This worked fine until the mice discovered my seedlings. Now I have to deal with them too. It is now my turn to get some satisfaction. Beware, chickens and turkeys enjoy roosting on tender seedlings, so give them other places to roost and you will have better luck with your seedlings.
“Hardening off” means to take a plant that is used to growing in a partly shaded, moist climate, and acclimate it to the harsh effects of heat and sun it may encounter when you plant it in the ground. When your plant fills up a one-gallon or 5-gallon container it may be ready for putting in the ground. Then, gradually get your plant used to more sun. Consider the time of year and don’t plant it out in the spring when all it has to look forward to is hotter and hotter days. Planting out in November gives the tender plant a few months of cool weather to get used to the heat and sun. Signs of too much sun include wilting, yellowing of the leaves where they are exposed to the sun, or brown spots on the leaves surrounded by yellow. Thirty minutes in full afternoon sun on a warm May afternoon will quickly kill many tender seedlings. Cactus are probably more likely to burn when moved into brighter sun because they cannot cool themselves with their leaves. You may want to temporarily shade a plant by placing some temporary filtered shade over it such as a branch pruned from another plant.
With some plants, I like to start the seed directly in the ground where I want it established. This technique works well for palo verde trees, ironwood, or other desert trees in the bean family. Scarify the seeds and plant 4-5 directly in the ground in the springtime. Water until the seeds germinate. When the seedlings are about 10-18 inches tall, pull out the weaker plants leaving the best. This method insures that the plant is acclimated to the sun, and develops a good tap root where it will eventually grow. Also, you don’t have to worry about killing the plant when you transplant it, or a pause in growth as the plant adjusts to having been transplanted.
Collecting plants from the wild is covered by two sets of laws. First, many native plants such as cacti, agaves, yuccas, lilies, elephant trees, orchids and others are protected under the Arizona Native Plant Law. To collect these plants you need permission of the landowner or managing agency, plus a permit from the Arizona Department of Agriculture. Generally, it is legal to collect seeds of all plants in Arizona, except sensitive, threatened or endangered plants. For a complete list of these, contact the Arizona Department of Agriculture at 602-542-4373. Most cacti such as the saguaro, barrel or prickly pear are not on this list, but some rare species are.
Second, most land management agencies require that you obtain a permit before you dig up any plants whatsoever; whether they are or are not protected under Arizona state law. Some land management agencies would like you to obtain a permit if you wish to collect commercial quantities of seed. Some agencies such as Organ Pipe Cactus National Monument do not permit any collecting at all except under special research permit.
Seeds of native plants are available from a number of sources:
Superior, ArizonaHave individual seed packets of limited species.
|The Desert Botanical Garden
Papago Park, PhoenixHave individual seed packets of limited species.
P.O. Box 27751
Tempe, Arizona 85285Has a variety of native wildflower and other native plant seed both in individual packets, as well as bulk
Many people who are interested in Arizona’s natural heritage enjoy growing wild plants from seed. It is fun, and satisfying. Even though it may take years for a plant to grow to any size, they do most of the work themselves; we just help them out a little at the critical points. If growing plants from seed sounds like something you want to try, start with simple and easy plants such as our palo verde trees or saguaro cacti. Your easy success with these plants may inspire you to grow more plants from seed. Remember; nothing ventured, nothing gained.
Native plants tend to attract more native wildlife. Propagating these plants yourself gives you the opportunity to have a landscape filled with a great variety of plants attractive to hummingbirds and other songbirds. Your yard will be a microcosm of Arizona’s outdoors and you and your family will get great joy from not only the special plants you grew yourself from seed collected from your favorite places, but also from the native birds that will be attracted to these great plants.