Let’s face it: Gardening ain’t for sissies. It’s tough work, squatting and kneeling as you water, plant and wrest stubborn weeds from the soil for hours under the hot, relentless sun. It can ravage your muscles and joints, and cause throbbing knee and lower back pain. Now, you can ditch the soreness, sweat and dirt, and garden from your sofa in your comfy, air-conditioned living room. And the only muscles you need to move are in your fingertips as they glide across your tablet or smartphone.