Planting, pruning and propagating: 5 things to do in the garden this week

1. Divide clumps of bearded irises. This is a practice that should be observed every three to five years. Otherwise, there will be a decline in the number and quality of your blooms. If the ground is hard, soak it well prior to extracting your clumps since digging is easier in wet earth. The bulb-like rhizomes of bearded irises are tough and do not need to be coddled. Simply pull them apart, taking care that a fan of leaves is attached to each. This foliage can be cut back to make the rhizomes easier to handle and plant. Add compost and other amendments where soil compaction is a problem. Planting depth should be shallow, with half of the horizontally oriented rhizomes exposed above ground level. 

2. Knowing when to harvest potatoes, onions, shallots, and garlic is easy. Just look for yellowing or flopping foliage. Store potatoes in a burlap sack for lasting freshness since air circulates through the bag even as light cannot get in. Store onions, garlic, onions, and other root vegetables in polypropylene onion bags. The breathable bags prevent moisture from accumulating around your harvested crop, extending its shelf life.

3. Succession plantings of beet, carrot, spinach, and lettuce seeds – ten or more seeds every couple of weeks – from now through November 1st will ensure a steady harvest of these crops from late fall until the arrival of spring. For fast, foolproof germination, sow seeds indoors in a cell tray with a humidity dome and a heating pad; kits including these three elements are available online for around $70. When your sprouts are 3-4 inches tall, harden them off outdoors in dappled shade for a week before transplanting them into the garden.  

4. If you are more interested in propagating ornamental plants than you are in raising vegetables, use the same apparatus described above for this purpose. Don’t be shy about your selections. Cuttings of roses, azaleas, and camellias should root readily enough, to say nothing of sages (Salvia species) and other softwood perennials and ground covers. To prepare cuttings, remove leaves at bottom of 3-5 inch stems and insert them into a 50:50 mix of perlite and peat moss. If you dip stems in root hormone (available at nurseries and online) to accelerate rooting, make planting holes with a pencil so that the root hormone does not rub off from being pushed through the soil mix. 

5. Summer pruning is recommended on deciduous fruit trees following harvest for these reasons. First, thinning branches brings more light into the interior of the tree which will benefit next year’s fruit; more sunlight make lager, sweeter fruit. Second, the height of the tree can be controlled. Third, winter pruning leads to explosive spring growth while summer pruning leads to a few inches of growth at most, so benefits of increased light and reduced height can be locked in for better quality fruit and ease of harvest next year. Fourth, summer pruning releases ethylene which leads to formation of more fruit buds, increasing next year’s crop. Finally, fruit-bearing branches are strengthened so they can hold more fruit without breaking in years to come.