Pomology
Basics
How to Germinate Your Seeds
Germinating Your Seeds is Fun and Easy. Methods vary by plant type. Seeds of annual plants have a shallow dormancy and do not need a winter to germinate, they only live one season. Annuals generally are buried to a depth equal to the size of the seed in moist well drained soil. Some, like tomatoes and peppers, require warm soil or a heat mat to germinate.
Perennial Seeds Need a Winter
Long-lived perennial plant seeds have mechanisms to prevent germination until conditions are right for successful growing. Perennial seeds go dormant over the winter and then need their dormancy broken in the spring. The techniques below are for perennial seeds only, do not use these techniques on annual or bi-annual vegetable, herb or flower seeds.
In the wild, dormancy is broken by spending time in the ground through the winter so that its hard seed coat is softened by frost and weathering. This cold moist period triggers the seed’s embryo to grow and eventually break though the softened seed coat in its search for the sun and nutrients.
Scarification
Some seeds require scratching or nicking the hard seed coat to allow moisture to enter the seed to begin germination. This mimics natures weathering or the gnawing of rodents. Medium to larger seeds can be nicked with a knife, filed or rubbed with sandpaper. Rub smaller seeds between sandpaper or emery paper. Hobby rock tumblers can be used to scarify larger seed volumes. Abrade only the outer coating, embryos should not be cracked or damaged to remain viable. Commercial nurseries scarify using solutions of sulfuric acid.
Hot water scarification is somewhat easier. Place seeds in an almost boiling pot of water at about 180°F (82°C). Allow the seeds to soak until the water cools to room temperature. Remove the seeds and sow, scarified seeds do not store well. Toss the seeds that float if viable seeds sink for that variety.
Some seeds have a double dormancy requiring both scarification first followed by cold stratification. Others such as Black Cohosh require both warm and cold stratification. See a varieties’ growing instructions for its scarification and stratification requirements.
Cold Stratification
There are six methods of stratification: cold water soaking, refrigeration, fall sowing, winter solstice sowing, outdoor treatment, and snow planting. Time to stratify seeds varies by species, though in most cases storing damp seeds at 39 to 40°F (4 to 5°C) for two to three months is sufficient. Try different methods. Split your seed packet between different methods, start dates or stratification lengths.
Cold Water Soaking
This method works best for medium and larger seeds a few weeks before last frost. You are trying to imitate snowmelt. Place seeds in a small jar and fill with cold water. Viable seeds should sink, although this is not true for all seeds. Many flat seeds or seeds with edges float. Change water daily, your are trying to wash germination inhibitors in the seed. Sow after two weeks. You can also try putting seeds in a small muslin bag and suspending them in the toilet tank. What could be easier, automatic rinsing.
Refrigeration
Wet extra strong paper towel with liquid kelp solution and ring out, fold in half. Liquid kelp is not necessary but it helps germination. Place seeds on half and fold again, press gently between your hands to get seeds in contact with the towel. Place inside plastic bag. Avoid thick walled freezer bags, they do not breath. Label with variety and date. Store in the refrigerator for two to three months depending on the variety. Check for moisture and rotting periodically. If seeds get brown spots and smell musty, they are rotting and should be tossed. Plant after three months whether germinated or not.
The advantage of the paper towel method is that you can see if the seeds are germinating. If germinated, cut paper towel and place on soil, keep moist. You can place seeds in bagged flats in sterile planting medium but the flats or pots take up more room in your refrigerator.
Fall Sowing
Direct sowing in the garden or pots in autumn is the traditional method in Europe. This method naturally exposes perennial seeds to winter conditions. Be sure to stake where you sow, and date. Wood popsicle sticks fade and rot over the winter. Use larger stakes — plastic stakes written with a black Sharpie last the longest. Plant at a depth appropriate for the variety. For seeds requiring light to germinate, just press on the surface.
Winter Solstice Sowing
A variation of autumn sowing is planting later in the winter, starting with the winter solstice on up to February. This method takes full advantage of winter cold and spring heaving and the growing energy of the earth as days lengthen. This works well for hard to start seeds like Good King Henry. We direct sow once in each month from November through March to find the right stratification window. In our zone 7b, mid-December was the proper sowing time to germinate Good King Henry.
Direct sow in place or sow in well drained flats. Do not use soil from your yard, it is usually compacted and hard for the seeds to break through. If necessary, screen soil through 1/4" or 1/2" hardware cloth and supplement over half with loamy compost or peat moss. Some cover their flats with plastic with holes or screens to let in snow. Make this a part of your annual winter solstice celebration. You can soak medium to larger seeds overnight to aid germination. For seeds that sink, floating seeds are not viable. Again, this varies by seed type. If seeds do not require light to germinate, sprinkle with dry soil to cover.
The harder your winter the later you can plant. If you have hard winters and it is very cold out, 30°F (0°C), put your seeds in the fridge for two weeks to reduce the shock before sowing outside.
Outdoor Treatment
This is our preferred method. This method is a variation of the bagged paper towel method but takes advantage of the fluctuating winter and spring temperatures. Instead of putting your bags in the refrigerator, place them outside away from direct light. We put them on the North side of our farmhouse, here in the northern hemisphere. Be sure seeds are protected from rodents. This method generally has a higher germination rate than the steady temp refrigerator method. If you plan to use this method and purchase your seeds after mid-February, you should wait until the following year to germinate them because you need cold late winter temperatures.
Snow Planting
This one is for the kids. After a heavy snow, go outside and broadcast your seeds on the snow where you want them to grow, preferably over a prepared garden bed. Have a snowball fight or toss snow over the seeds so birds do not eat them all. This method works best for varieties that can handle cold but do not require cold stratification such as hardy annuals, biennials or short lived perennials.
Surface Sowing
Keep your surface sown seeds moist until the plants are established. If direct sown seeds dry out in your climate from sun or wind, try covering with a single layer of burlap, light colored cotton sheet or half an inch of loose grass clippings. Remove burlap or sheet after germination. Shading with a window screen or white row cover above them the first season will help prevent drying in hot climates. You can also cover with clear plastic until germination to retain moisture, but be careful not to overheat. As soon as sprouts appear, again remove covering.
Some Need Light
Some seeds require light to germinate, sow these seeds on the surface and gently press into contact with the soil. Seeds requiring light to germinate will be indicated both in the growing instructions and will have a sowing depth of ‘surface’.
Good growing!
Lychee
How to Grow Lychee From Seed
Lychee fruits contain a single seed that you can plant to grow more lychee fruits. Follow the steps below to grow lychee from seed:
- Save the seed. Buy the fruit and enjoy it, then keep the large, brown seed at the center. You’ll want to pick fruits that have fully ripened (seek larger lychees with a reddish-purple rind) for the sake of the viability of your eventual fruit.
- Soak the seed for three days. Gently rinse the seed and then pat it with paper towels. Soak the seed in a small bowl filled with warm water. The seed will need to sit for three days, which helps with germination. Replace the water each day for freshness, and when the exterior of the seed begins to crack, it’s time to plant.
- Plant the lychee seedling. Get a container with drainage holes that’s almost a foot tall and fill it with potting soil. The soil should be slightly acidic. Bury the seed fully, about an inch into the soil. You’ll want to mimic a subtropical environment for growing lychee trees: wet and warm. Keep the pot in a warm room that stays in the seventies, but keep your growing lychee plant away from direct sunlight. In the early stages of growth, shade is best.
- Water and relocate your plant. Lychee trees need more water than the average houseplant. Give it water every other day, checking the soil to see how moist it is. When green lychee leaves begin to poke out of the soil, move your pot toward more direct sunlight.
- Watch your plant’s growth. Lychee trees can grow quite tall—up to ten feet—so you’ll want to prune by cutting branches and leaves from the top to keep it in check. After your first year, repot your plant, giving it a larger home. As it gets bigger, your plant will need more sunlight; because of this, lychee plants tend to grow best outdoors in direct sunlight. As evergreen trees accustomed to tropical climates, lychees grow best in hardiness zones ten and eleven.
Orange
Can You Grow Store Bought Oranges
By: Teo Spengler
Anyone looking for a cool, indoor gardening project may want to try growing an orange tree from seeds. Can you plant orange seeds? You surely can, using grocery store orange seeds or seeds from oranges that you get in the farmer’s market. It may take up to a decade to see fruit from your plant, however. It’s fun and easy, and even if you don’t get fruit, you can bring a vibrant green plant into the world with sweet-smelling leaves.
Growing Seeds from Oranges
It’s no surprise that you can grow orange trees from seeds inside the fruit. Every other fruit grows that way, so why not oranges? Anyone who has ever peeled and eaten an orange knows that the fruit can have a dozen seeds in it, or even more. The bigger news is that most seeds from oranges can grow into plants, you can even grow store bought orange seeds. That doesn’t mean you’ll necessarily succeed the first time, but you probably will over time.
Can You Plant Orange Seeds?
It may be hard to believe that the seeds you pile up as you are consuming an orange are potential orange trees. It’s true though, even grocery store orange seeds, planted correctly, have a good chance of growing if you plant them right. The seeds from sweet oranges usually come true from seed, producing plants like the parent tree, but “Temple” and “Pomelo” are two varieties that won’t. The first step is preparing the seeds for planting. You’ll want to select plump, whole, healthy seeds, then clean off any pieces of orange on them. Soak the seeds in a bowl of tepid water for 24 hours to assist in germination.
Orange Tree from Seeds
Once the seeds are cleaned and have been soaked, it is time to plant them. If you live in a warm climate like USDA plant hardiness zones 10 or 11, you can plant the seeds outside. Those in cooler regions can plant in pots indoors.
In either case, grow your store bought orange seeds in well drained soil. If you are growing them in pots, use small containers with at least two drain holes per pot. Fill the pots with soil or sterile potting mix made up of equal parts milled peat and small-grain perlite. Press two seeds into the surface of the soil in each pot, then cover them lightly with the soil or potting mix.
Keep the soil moist and the pots in a warm spot until the seeds sprout. Germination can occur within a week, but it may take several weeks. Each seed may produce up to three sprouts, and you should prune out the weakest. Transplant the healthiest sprouts into larger pots filled with citrus formula potting soil and place them where they get direct sun. Water and fertilize with citrus fertilizer and watch your new plants grow.
Citrus: Lemons, Oranges, and Limes
By Catherine Boeckmann
Although Citrus is a subtropical genus, fragrant and flavorful citrus fruit can be grown almost anywhere. From lemons and limes to oranges and grapefruit, citrus trees are fun and rewarding plants to grow—but not without some work! Here’s how to grow citrus trees at home.
About Citrus
Citrus plants are native to tropical and subtropical regions of southern Asia, Australia, and the South Pacific, but have been brought to all corners of the globe thanks to human cultivation. These woody plants range in size from small shrubs to large trees, and their fruit is just as variable in size and shape—just take a walk down the fruit aisle at your local supermarket! Standard-size grapefruit and orange trees can grow 18 to 22 feet tall, whereas dwarf citrus varieties only grow 8 to 12 feet tall (or smaller, if kept in containers).
Gardeners in the warmest parts of the United States (USDA Hardiness Zones 8-11) can grow citrus outdoors year round, while colder-climate gardeners (Zones 7 and colder) should consider growing lemons, oranges, limes, and other dwarf citrus trees in containers to enjoy fresh citrus fruit, too. Read more about growing citrus in containers here.
Lemon trees in containers
Most citrus varieties are self-fertile, so only one tree is typically needed for fruit production. On average, fruit bearing begins when the trees are between 3 and 6 years old. However, exact timing will depend on the type of citrus, the cultivar, your climate, the health of the plant and its care, and other factors. Flowering is not seasonal, but occurs during warm weather and regular rainfall. In fact, flowers and fruits may appear on the plant at the same time!
PLANTING
When to Plant Citrus Trees
Early spring is the best time to plant citrus trees outdoors in the parts of North America where they can be grown outside (Zones 8-11), since they’ll have the entire summer to settle in before cooler weather arrives. If frosts occur in your area, wait to plant until a spring frost is no longer a threat.
In the citrus belt (a loosely defined area including southern California, parts of Arizona and Texas, and Florida), trees can be planted at any time of the year. Citrus can be planted indoors in containers at any time of the year.
Choosing and Preparing a Planting Site
Warmth helps citrus fruit mature and sweeten, so citrus trees should be planted in a warm, sunny, and wind-protected area—planting along the southern side of a house or other structure will provide all three features. In cases where sweetness isn’t a concern (with lemons and limes, for example), extra warmth is less important.
Citrus trees need well-draining soil. If they sit in too much water, the roots can rot. If the soil is not well-drained, plant the trees on a slight mound to prevent waterlogging.
Citrus trees prefer slightly acidic soil, so consider testing the pH of your planting site and amending accordingly.
Standard-size citrus trees should be spaced 12 to 25 feet apart and dwarf citrus trees should be set 6 to 10 feet apart. The exact distance depends on the variety. The bigger the fruit, the farther the distance. Orange trees
How to Plant Citrus Trees
After unwrapping or removing the tree from its container, first inspect the root ball. If the roots seem tangled or like they’re growing in circles, gently score up and down the sides of the root ball several times with a knife. This breaks up the bound roots and encourages them to grow outward.
Dig a hole that’s about 1.5 times the width of the root ball and about as deep as the root ball is tall. Like most trees, citrus trees should be planted slightly above the depth that they were at in the container; planting too deeply can cause water to pool around the trunk, leading to rot and disease. Planting slightly higher than the surrounding soil ensures that water will run away from the trunk.
Note: If planting a grafted variety of citrus, make sure that the graft union is 4 to 6 inches above the soil level. If planted too close to the ground, roots may form from the graft union, defeating the whole purpose of grafting! Place the tree in the hole and backfill with soil. When the hole is half filled, spray with water to settle it and flush out air pockets, then continue filling with soil. Water again to settle the soil after the hole is filled.
Tip: Do NOT add special soil or fertilizer to the planting hole. It’s best to let the tree get used to the soil nutrient levels and consistency that are already present in the planting site. Starting Citrus Trees from Seed
Citrus trees can be started from seeds, but they usually don’t breed true, which means that you may not get the same quality fruit! It’s also possible that citrus trees grown from seed won’t flower or fruit at all. Nonetheless, growing a citrus tree from seed is a fun experiment.
To start citrus trees inside from seeds, remove the seeds from the desired fruit. Soak the seeds overnight in water and plant them 1/2 inch deep in moist potting soil.
Cover the pot with a plastic bag or wrap and let it sit in a warm and sunny spot for a few weeks until the seeds start to grow. Then, remove the plastic but keep the pot near a warm and sunny window as the seedlings grow.
GROWING
How to Care for Citrus Trees
A few weeks after planting, and for the first few years (before fruit-bearing age), feed the tree a balanced (such as 10-10-10) fertilizer. Learn more about soil amendments and preparing soil for planting.
For newly fruit-bearing trees, provide nutrients to continue branch and leaf growth, but also to replace nutrients lost by fruit forming. A “citrus blend” fertilizer is ideal.
Check manufacturer’s directions, ask a garden nursery, or consult your local cooperative extension as to how often and how much fertilizer to apply during each year of a tree’s growth.
Because of citrus’ shallow roots, mulches are not recommended for citrus trees. If the trees are located in a cultivated garden bed where mulch is used, keep at least 12 inches of bare ground between the tree trunk and the mulch. Pre-emergent herbicides (NOT post-emergent) may be used sparingly around mature trees to prevent weed seeds from germinating, but hand-weeding is preferred. (If using herbicides, be sure to follow dosage and application instructions carefully.)
Don’t plant groundcover plants around the base of citrus trees, as the trees have shallow roots that will struggle to compete for nutrients.
Citrus trees bloom in the spring and fruit starts to develop shortly thereafter.
Fruit thinning is unnecessary for citrus trees, as they typically experience something called the “June drop.” In late spring or early summer (May or June for most of the country), citrus trees naturally drop a number of their immature fruit, which allows the tree to focus its energy on maturing the rest of its fruit.
RECOMMENDED VARIETIES
Grapefruits - ‘Red Blush’ (pink flesh), ‘Marsh Seedless’ (white flesh), and ‘Star Ruby’ (red flesh)
Lemons - ‘Eureka’ and ‘Sun Gold’https://www.almanac.com/content/how-make-pomander-balls
Limes - ‘Bearss’ and ‘Rangpur’
Mandarins - ‘Clementine’ and ‘Satsuma’
Sour Oranges - ‘Bouquet de Fleurs’ and ‘Seville’
Sweet Oranges - ‘Valencia’ (Valencia), ‘Ruby’ (Blood), and ‘Washington’ (Navel)
Tangelos - ‘Minneola’ and ‘Orlando’
HARVESTING
How to Harvest Citrus
The length of time required for the fruit to ripen depends on the type of citrus and the cultivar. Some oranges can take up to 15 months to mature fully, while others need only 8-12 months. Citrus fruits will not ripen off the tree, so refrain from picking them too early.
The best indicator of ripeness is taste.
Harvest the fruit by cutting them off with pruning shears or by pulling the fruit stalk from the tree.
How to Store Citrus Fruit
Undamaged citrus fruits can be stored for 3 to 8 weeks at normal refrigerator temperatures.
Prolonged exposure to cold temperatures can decrease the fruit’s quality, so consider leaving the fruit on the tree and only harvesting when needed.
WIT AND WISDOM
Make your own air freshener: Slice some lemons, cover with water, and let simmer in a pot for about an hour. Make pomander balls for the holiday season. See more household uses for lemons.
PESTS/DISEASES
- Aphids
- Spider Mites
- Root and Crown Rots
- Fungal Leaf Spots
- Fruit Flies
- Tristeza Virus spread by Aphids