Discover the joys of a low-maintenance garden. If you go to the cottage for a month every summer, keep your garden low-maintenance by planting drought tolerant shrubs and perennials. Totally avoid plants that require constant special attention like pruning, staking, deadheading. Minimize lawn mowing by converting some or all grass to ground covers. Delay or stagger planting of vegetables so they won't mature while you're away.
Group houseplants together in a sink or bathtub.
Water well, then drape plastic over the sink or tub. Use bamboo stakes to keep plastic from contacting plants. Tape around edges of sink or tub. This creates a self watering, terrarium like environment for a 2-3 week absence. Add a source of light, like a reading lamp with a timer, plced at least 50cm from plants to give 8 hours of light.