Of Nematodes and Black Rot
It was another interesting Master Gardener class on Friday. The instructor, a horticulture professor at OSU, presented his entire semester course on plant diseases in 4 hours. By the end, my head was ready to explode, convinced that the apocalypse is just waiting to decend upon Plant World because of all the varied and hideous ways in which living green things can be destroyed by fungi, viruses, bacteria, and nematodes. (And that's not including all the damage done by insects.) The lesson to be learned was that death and destruction await your gardens and trees if you don't do things Exactly Right. And heaven forbid if you get an infection in your soil....because you can't get rid of it. It was the plant version of a driver's ed scare and shock video, with nematode galls and black rot instead of blood and gore.
Tip of the day #1: Beware of discounted plants at retail stores because there may be more wrong with the plants than just a little neglect.
In fact, a retailer might discount plants because they are infected with some disease, and once you bring home that disease, you may have difficulty getting rid of it, even long after the affected plants die. Luckily, most diseases are species specific, but if you bring home some dire disease of, say, petunias, you might have trouble growing pentunias from there on out.
Tip of the day #2: Water in the morning, and keep the water off the leaves.
I already knew that it was better to avoid getting water on plant leaves, but I never gave it much thought as to why. Well, I knew that it encouraged black spot on roses, but I'd never applied the same rule to, say, tomatoes. Also, I'd always been told that it was best to water in the early morning or the evening, which I largely attributed to water evaporation more than anything else. But, no, it's all about disease. The majority of plant diseases are caused by fungi, and fungi are typically quite fond of moisture. So, if your plant leaves get damp in the evening from the watering you do after work, they stay damp all night, stressing the plant and creating a perfect environment for encouraging disease. It's like you or me going out on a cold, damp day in winter without a coat and hat. If we're healthy, chances are nothing will happen, but if our immune systems are down, chances are much better we're going to come down with a nasty bacterial infection or virus. So if a plant is suffering from nutrient deficiency, or a lack of immunity against a particular disease (like roses and black spot), or injury from insects, or any of the four horsemen of the plant apocalypse, they just might get something nasty from your helpful watering late in the day.
Tip of the day #1: Beware of discounted plants at retail stores because there may be more wrong with the plants than just a little neglect.
In fact, a retailer might discount plants because they are infected with some disease, and once you bring home that disease, you may have difficulty getting rid of it, even long after the affected plants die. Luckily, most diseases are species specific, but if you bring home some dire disease of, say, petunias, you might have trouble growing pentunias from there on out.
Tip of the day #2: Water in the morning, and keep the water off the leaves.
I already knew that it was better to avoid getting water on plant leaves, but I never gave it much thought as to why. Well, I knew that it encouraged black spot on roses, but I'd never applied the same rule to, say, tomatoes. Also, I'd always been told that it was best to water in the early morning or the evening, which I largely attributed to water evaporation more than anything else. But, no, it's all about disease. The majority of plant diseases are caused by fungi, and fungi are typically quite fond of moisture. So, if your plant leaves get damp in the evening from the watering you do after work, they stay damp all night, stressing the plant and creating a perfect environment for encouraging disease. It's like you or me going out on a cold, damp day in winter without a coat and hat. If we're healthy, chances are nothing will happen, but if our immune systems are down, chances are much better we're going to come down with a nasty bacterial infection or virus. So if a plant is suffering from nutrient deficiency, or a lack of immunity against a particular disease (like roses and black spot), or injury from insects, or any of the four horsemen of the plant apocalypse, they just might get something nasty from your helpful watering late in the day.