Zinnias are my favorite annual summer flowers, and I say this for four reasons:

• They are as colorful as a kaliedoscopic rainbow.

• Their many petaled blooms, like those ruffled collars seen on 17th-century Dutch nobility in paintings from that era, have no rival, with the exception of dahlias, to which certain large snowballish zinnia varieties bear a strong resemblance.

• They make an outstanding cut flower bouquet, staying fresh in a vase for two weeks when properly handled. (See the “tip of the week” for instructions.)

• They are ridiculously easy to grow from seed. Press zinnia seeds into the soil, just beneath the soil surface, leaving them exposed to the light. Then sprinkle some soft soil or compost over the top of the seeds and, as long as soil is kept moderately moist, you should see them sprout within a week.

It may take two months for your seed planted zinnias to bloom, but once they start they will continue to do so until late into the fall.

If you were to plant the seeds now, you would still get a good month or two of flowers. In addition, once your flowers fade, you will have a huge supply of seeds for next year’s zinnia crop.

Some people are discouraged from growing zinnias because of their tendency to develop powdery mildew. But this is not the zinnias’ fault. No, zinnias are without sin-nias!

When you think of zinnias, think summer, think desert heat, think dry air. Zinnias become mildewy either because they are watered overhead or because they are deprived of circulating air, or both. If you can keep water scrupulously at the roots and avoid getting zinnia leaves and flowers wet, making sure that they absorb most of the day’s sun and have plenty of air moving around them, and are far removed from shade-producing trees, your plants should do just fine.

Zinnias, then, are the quintessential sun-loving flowers.

Fittingly, the man for whom zinnias are named, Johann Gottfried Zinn, was the quintessential 18th-century botanist-physician. Prior to the era of mass-produced pharmaceuticals, physicians were typically botanists, too, since nearly all medicines came directly from plants. Immediately before he became a faculty member of a medical school, Zinn worked as the director of a botanical garden.

Coincidentally, perhaps, zinnias are highly medicinal. Their habitat extends from the American Southwest into Mexico, all the way down through Central and South America.

The Navajo consider zinnias a sacred Life Medicine, using their flowers and leaves in herbal remedies for a variety of illnesses. Navajo children are encouraged to eat the flowers to become wise. The flowers are also of value in the manufacture of dyes and paints.

Zinnias come in many sizes, ranging from the dwarf ground cover type that grows up to a height of only 12 inches, to giants that may reach 4 feet. You will not find the taller zinnia varieties growing at the nursery since they do not transplant well. Dwarf varieties are more successfully transplanted and that’s why you see them in nursery containers. But even with the dwarfs, transplanting is hit and miss and if you do transplant them, it should be done as soon as they appear in the nursery. It’s a good idea, if you desire bushier plants when germinating the tall varieties, to pinch them back when they are around 6 inches tall.

QAbout seven years ago, I was eating an orange I bought from the local grocery store. I was standing at my kitchen sink, and I took one of the seeds and stuck it in the dirt of a tiny plant that was on the counter. Weeks later, a little sprout appeared!

Now, it is a vibrant medium-sized tree in my back yard. However, it NEVER produces oranges, or even flowers for the bees. I’ve put oranges near it and show it pictures of orange trees but it is just not inspired by my tactics.

Can you tell me if there is a way to make this tree more than just my awesome sink tree, and actually have it make me an orange?

— Michael Foster, Long Beach

AThe earliest an orange tree grown from seed has been known to flower and fruit is seven years, but it could take up to 15 years or more to produce your longed-for oranges.

I guarantee that your tree will eventually flower and fruit, but to hasten the process you should do everything possible to hasten the growth of the tree. Every plant needs to reach a certain size before it enters its adult or reproductive stage.

In this regard, the age of your tree is really insignificant. Thus, the faster it grows, the sooner it will flower. I would therefore give it fertilizer on a regular basis and keep it well-irrigated. Don’t fertilize after summer ends since you don’t want your tree putting on sensitive new growth, that could die back in a frost, as winter approaches.

You should also remove lawn grass out to the canopy perimeter or drip line of your tree, if not beyond, since lawn grasses compete with tree roots for water and fertilizer.

Trees that grow from seeds are like children. You never know what they will turn out to be.

The quality of fruit from a seedling tree such as yours is typically bland, but you never know. Your tree could produce the sweetest oranges on Earth.

If you want to shorten the process of making flowers and fruits from a homegrown tree, consider cloning an orange tree whose fruit you fancy, after getting permission from the owner to do so.

Take well-developed terminal shoot cuttings 1 foot in length that are as thick as those chubby, kindergartner-friendly pencils. Remove all the leaves except the two at the top of each cutting. Make a rooting medium that is 2/3 construction grade sand and 1/3 sphagnum peat moss. Insert half the length of the stems into the rooting medium. Give cuttings bright light but no direct sun and keep rooting medium moist but not overly wet. Roots should start to form within two to three months.

Tip of the week

To maximize vase life of your zinnias, follow the steps below. In truth, many of these guidelines are applicable to maximizing vase life of cut flowers, from agapanthus to roses, in general.

1. Cut flowers in early morning, just after dew has evaporated.

2. Cut flowers that have just begun to open.

3. Cut into the stem 12 inches down from the flower.

4. Cut stem at 45-degree angle.

5. Fill vase with warm water and add floral preservative.

6. Cut off any leaves on stem that would be submerged below water line in vase.

7. Cut off bottom half-inch of stem at 45-degree angle, insuring maximum absorption of water.

8. Place arrangement in bright area but avoid overly sunny exposures that may cause wilt.

9. Replace water and floral preservative every two days.

10. The moment a flower begins to wilt, remove it and its stem to enhance longevity of remaining blooms.

The above instructions pertain to long-stemmed zinnias, but I see no reason why the compact or dwarf zinnia flower heads could not be cut and floated in a bowl, just as most flower heads, sans stem, can be floated for tablescape purposes.

Make sure you change water in your bowl and add floral preservative every two days. You can make your own floral preservative by mixing 2 cups of Sprite or 7-Up and a 1/2 teaspoon of chlorine bleach into 2 cups of warm water (recipe courtesy of thoughtco.com).