Botanical writer and plant-hunter, nephew of Grace, Lady Campbell, founder of Crarae glen garden in Argyll. He was born in London and brought up in Ingleborough where he became interested in rock garden plants. He brought his personality to the page with My Rock Garden and The English Rock Garden. In 1913 he visited Kansu Province in northwest China and in 1919 visited Yunnan with Euan Cox, who introduced Juniper coxii, the coffin-tree juniper. He died on a Burmese mountain. Plants discovered by him include Gentiana farrerii, Cypripedium farrerii and Viburnum fragrans.
Sixty-gallon rain barrels are available for about $100 from various regional non-profits working on water conservation and pollution (in the DC area, from the Interstate Commission on the Potomac River Basin: http:///cms/?option=com_content&view=article&id=50&Itemid=69 ). You can also get larger tank-style ones for under $500 (a better deal if you are planning to buy more than four of the 60-gallon types). They will fill with each rain (one inch of rain drops about 600 gallons on a typical roof) and might tip the balance regarding watering. I use water from ours for watering the indoor plants as well.
Many gardeners report success with regular household vinegar. It has 5% acetic acid and 95% water. But for an even more effective weapon, vinegar with 20% acetic acid is sold as a non-toxic herbicide. I recommend experimenting with diluting the 20% vinegar to make it last longer. University studies say that 10-20% vinegar is effective. Vinegar is a quick-acting, non-selective contact herbicide and its residues degrade promptly in the soil. Foliar contact results in rapid dehydration of annual weeds and grasses, and top growth reduction of herbaceous perennial weeds and grasses. 20% vinegar may be applied up to two days before harvest. Find 20% vinegar here. 20% vinegar is non-food grade and is strong. Read application instructions carefully.