Please see http://softadventure.net/gardeningplantID.htm

Should one cut fortnight lilies back each year? If so, in winter?

Should one cut off the flower heads of lavender once bloom is finished?

HH

Should one cut off the flower heads of lavender once bloom is finished?

HH

Immediately after blooming, cut the top third of the stem off. (The
part with the grey leaves, not to be confused with the flower stalk)

HH wrote:
Please see http://softadventure.net/gardeningplantID.htm

Should one cut fortnight lilies back each year? If so, in winter?

Fortnight lilies (Dietes iridiodes, also known as D. vegeta) are
evergreen and should not be cut back. The flower stalks will rebloom if
left alone. Removing them can prevent flowering for a season. Only
remove the stalks if they are obviously dead, and cut back only dead
portions.


Should one cut off the flower heads of lavender once bloom is finished?

Yes, removing spent flowers will promote new growth and (later) more
flowering. However, when cutting, always leave a few green leaves. If
you cut below the lowest green leaf, the stem will die.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/