|
|
|
|
|
|
Garden Questions of the Week
|
Timely Gardening Information Customer service staff at Hole's regularly post up the most commonly asked questions. |
|
My cedars are turning black on the bottom branches. What’s the problem?
Practical Answer: Dog urine is the most likely culprit. Dog urine contains high levels of salt, which can burn foliage, turning it black. If possible, wash down the affected area immediately after the dog urinates. Then do your best to keep the dog away from the tree in the future. You may have to put up a barrier. The Science Behind it: We once had a customer who swore that window-washing spray caused the same blackening on the top of his cedar. Both urine and many cleaning solutions contain ammonia, so that may be possible.
My seedlings tend to become leggy. Some of them even flop over. What causes this?
Practical Answer: Leggy seedlings are usually caused by a shortage of light, combined with warm day temperatures and cool night temperatures. Be careful to maintain a constant temperature as your seeds germinate. Once the seedlings emerge, however, reduce the soil and air temperature as soon as possible. If you don’t check your flats regularly, it’s easy to miss this critical transition. I’ve checked flats at nine in the morning and returned at three in the afternoon to find the seedlings fully emerged. They’re just like teens—you blink and they’re two feet taller! The Science Behind it: Once your seedlings emerge from the soil, reduce the heat! Warm soil is a seed’s best friend, but a seedling’s worst enemy. Be sure your flats continue to get plenty of light, however. Stretched seedlings tend to flop over because their spindly stems can’t support the weight of the leaves. They’re also more vulnerable to disease. You may spot a few dead seedlings in one spot, and watch in horror as that one spot becomes a slowly widening circle. This means that damping-off disease has set in. You’ll have to discard your plants and soil, wash and sterilize your flats and tools, and try, try again. I often illustrate plant diseases using a simple triangle. A plant will fall prey to a disease only if three conditions exist at the same time: • the organism that causes the disease must be present. • the plant must be susceptible to that particular disease. • the environment must be right for infection (for example, some fungi thrive when there’s lots of humidity). If you can eliminate even one corner of this triangle, infection cannot occur.
What is the optimum soil temperature for germination?
Practical Answer: Every seed has an ideal temperature for germination, from 15-26°C. I try to keep my soil within this range, but it takes a lot of trial and error to get it right! The Science Behind it: For the most part, bedding plants fall into two categories: those which need cool soil for germination (15-20°C), and those which need warmer soil (21-26°C). For the best results, you should keep this temperature constant, day and night. The simplest way to do this is with heating cables. They’re not that expensive and can be purchased at any good garden centre. Remember that soil temperature can differ significantly from the air temperature. Monitor your flats with a temperature probe—it’s well worth the few dollars it costs! Check your flats twice a day, in the morning and evening, by placing the probe at the depth of the seed—no deeper. This will tell you the exact soil temperature. At the greenhouse we use an infrared gun—just point and shoot for an instant soil-temperature reading—but that’s well beyond most people’s budget.
Is my windowsill too cold in the winter for starting seeds?
Practical Answer: Usually, the temperature on a windowsill fluctuates too much. Seeds prefer consistent warmth for germination. The Science Behind it: Cold air spills down the glass, chilling the soil overnight. Heating cables can reduce this problem.
How should I water my seedlings?
Practical Answer: Carefully! In the greenhouse, I put it this way: whoever waters the plants controls the profits. Gardeners make two main mistakes when watering seedlings: making the flats too wet (or not wet enough), and washing the seeds away to the edges of the flat by using too strong a stream of water. Use a seedling nozzle on the end of your watering can, never a regular nozzle. Seedling nozzles produce a very fine droplet size that won’t wash away the seeds. Even better, use a simple mister bottle, which produces the finest droplets and reduces the risk of washing away the seeds. The Science Behind it: I agree with Mom—you do have to water seedlings carefully. The job is easier if you thoroughly moisten your seeding mixture before adding the seeds. After that, you only need to replace any moisture that’s lost. Don’t give the flats any more water than that. Seeds can literally drown if they’re constantly waterlogged. They need both moisture and oxygen to germinate. Once you’ve moistened the soil in the flat with a watering can, you only need to add enough water to keep it from drying out. Keep your mister bottle handy, and spray the surface from time to time. Give your seedlings the moisture they need! • Moisten the soil mix thoroughly before planting. • Sow the seeds. • Spray the soil surface well with a mister bottle. • Cover the flats with clear or black plastic or fabric until the seedlings emerge. • Mist every time the soil surface begins to show signs of drying out.
When do flowers begin to form for the next growing season?
The Science Behind it: Spring-flowering shrubs form flower buds late in the growing season and bloom as soon as the weather warms in the spring. However, their buds need to accumulate enough hours of chilling during the winter before they’ll bloom. Summer-flowering shrubs form buds on the new branches that emerge early in the season and bloom later, in the summer.
Why is a mock orange called a mock orange?
Practical Answer: If you ever walk by a mock orange in full flower on a warm summer day, you’ll immediately understand why it’s been given this name. The flowers have a delicate orange scent that I just adore. The Science Behind it: The scent is the only trait that relates the mock orange to the citrus tree: they’re entirely different species. Many people call mock orange the jasmine tree because of its fragrance.
Which works better, chemical or organic fertilizer?
Practical Answer: Both work equally well. As long as your plants get the nutrients they need, they don’t really care how they get them. I like to use water soluble fertilizers because they act so quickly and they are so easy to use, but many people achieve excellent results with fish fertilizers, kelp meal, manure teas, and even bat guano. The Science Behind it: All fertilizers are actually “chemical” fertilizers, in that they deliver the same elements and compounds to your plants. However, organic and non-organic fertilizers differ in the way they deliver these nutrients. When you add manure to your soil, for example, microorganisms in the soil digest it, breaking it down into separate compounds such as ammonium, nitrates, phosphates, and iron oxides. Chemical fertilizers, such as 20-20-20, also contain ammonium, iron, phosphates, and so on. Unlike organic fertilizers, however, they don’t have to be broken down before releasing nutrients to the plant. In either case, the plant eventually absorbs the same compounds in the same form, whether it’s from an organic or non-organic source. Keep in mind, however, that organic fertilizers provide more than short-term benefit to your plants. Because they take time to break down, they provide a long-term reservoir of nutrients in your soil. They also improve your soil’s texture and moisture retention. The organic fertilizers generally have a low analysis (i.e., fish fertilizer is approximately 3-1-1), so you need larger quantities to provide the same amounts of nutrients as a chemical fertilizer.
What is manure tea?
Practical Answer: I’ve never made manure tea, or compost tea, but a lot of people swear by it. Like the name suggests, it’s a liquid fertilizer made by soaking manure or compost in water. You brew it in much the same way as you would Orange Pekoe, but in a bigger pot! Just shovel some manure or compost into a burlap bag and tie it shut. Then immerse your “tea bag” into a large bucket or barrel of water, cover it, and leave it to steep for a few days. Before using the liquid on your plants, be sure to dilute it to a very light brown colour. Use the tea in place of regular water. In my opinion, the amount of work in brewing this tea far outweighs the benefit to the plants, but don’t let me stop you from giving it a try. I wouldn’t use it on edible flowers, however, in case of disease. The Science Behind it: Keep a few points in mind when using manure or compost tea: • Manure may contain plant diseases, and seedlings are especially susceptible. • Manure teas may contain high levels of ammonia that can injure seedlings. • Because tea is a weakened solution of manure, it may not contain enough nutrients for rapidly growing plants. As with any manure, the composition varies depending on the age and origin of the manure. • Manure can contain disease organisms that may pose a human health risk.
Where should I shop? What features should I look for in a greenhouse?
Practical Answer: You can often predict the quality of the plants the moment you walk through the door. If the building itself seems clean and organized and has knowledgeable staff, you can be sure that the plants receive the care they need. The Science Behind it: Healthy, vibrant-looking plants are the first thing you should look for, but the staff is also key. There must be enough of them, and they need to know the business. If you have a question, or are looking for suggestions, there should be someone who’s ready and able to help you. You should also ask if they grow the plants themselves or if they are brought in.
How many plants do I need to fill a specific area? Is there an overall formula?
Practical Answer: It all depends on the variety. The tag or seed packet should give you a good idea of how big the plants will grow. I always tell people to plant thickly, leaving just enough room for each plant to grow to its fullest. Nothing beats a nice, solid flowerbed for lots of lush colour. The Science Behind it: Mom’s right—there’s no magic formula. You need to know how big the plants will be when they mature. For many of the popular annuals, though, you can expect to plant 30–35/m2 (3–4/sq. ft.).
What is a flat? A pack? What is the difference in pack sizes?
Practical Answer: A flat is just the tray in which you carry around packs of young plants. It looks like a baking pan. Packs, on the other hand, resemble smaller muffin tins, with their individual cells. The Science Behind it: A flat is the rectangular container (plastic tray) that holds the packs. Most seedlings are sold in packs—thin, rectangular plastic containers holding from 1 to 6 (or more) individual plants. Packs come in many different sizes, each with its own number. For example, the Jumbo 606 has six large packs per flat, with six cells per pack. In other words, a flat with a 606 insert holds a total of 36 seedlings. We use the Jumbo 606 because it allows us to grow a much larger and healthier plant. The most common size you see at a greenhouse is usually the 1206, which has half the space per plant but holds 72 plants. A 1501 has 15 individual packs with only one cell each. This would be used for larger, more mature plants.
I love butterflies. How do I attract them to my garden?
Practical Answer: Just plant plenty of their favourite flowers. Among the annuals they like best are asters, nicotianas, petunias and thunbergia. Wave and Tidal Wave petunias work well and provide some beautiful colour to your beds. The Science Behind it: Butterflies have an astonishing sense of sight and smell, and can detect their favourite flowers from far off. They will begin to appear almost as soon as your plants are in bloom. As long as your garden provides a plentiful source of nectar, you can be sure that the butterflies will drop by for regular visits.
Can begonia plants be split?
Practical Answer: No. Both fibrous and tuberous plants would be damaged. Always start your begonias from seed, tubers, or new plants. The Science Behind it: You can take cuttings from your begonias, but because these stems are very fleshy, even this procedure can be challenging.
I've overwintered my geranium but don't know what to do with it now. What should I do?
Practical Answer: In February, trim the stems to one third their original height and place them in as much direct sun as possible. • Water just enough to moisten the soil. Allow the top of the soil to dry out between waterings. • Fertilize with Lois' Growing Season 20-20-20. The Science Behind it: When new growth appears, remove the plant from its pot and shake off the old soil. Using new potting soil, repot into a container just large enough to contain the roots. Fertilize every two weeks with 20-20-20. • Take leaf cuttings off the plant. Use a sharp knife to cut off the new leaves cleanly at the base. Dip the cut end in a rooting compound, shake off the excess and plant the leaf in a good quality starter soil mix. Place in a sunny window and keep evenly moist. Fertilize every second week with 20-20-20 at half strength. |
|
